EPA-460/9-73-001
AUTOMOTIVE GAS TURBINE
ECONOMIC ANALYSIS
Investment Cast Turbine Wheel
Supplement
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Water Programs
Office of Mobile Source Air Pollution Control
Advanced Automotive Power Systems Development Division
Ann Arbor, Michigan 48105
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EPA-460/9-73-001
AUTOMOTIVE GAS TURBINE
ECONOMIC ANALYSIS
Investment Cast Turbine Wheel
Supplement
Prepared By
Robert T. Hall, G. Music
Williams Research Corporation
2280 W. Maple Road
Walled Lake, Michigan 48088
Contract No. 68-01-0405
EPA Project Officer:
William C. Cain
Prepared For
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Water Programs
Office of Mobile Source Air Pollution Control
Advanced Automotive Power Systems Development Division
Ann Arbor, Michigan 48105
July 1973
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This report is issued by the Office of Mobile Source Air Pollution
Control, Office of Air and Water Programs, Environmental Protection
Agency, to report technical data of interest to a limited number of
readers. Copies of this report are available free of charge to
Federal employees, current contractors and grantees, and non-profit
organizations - as supplies permit - from the Air Pollution Techni-
cal Information Center, Environmental Protection Agency, Research
Triangle Park, North Carolina 27711 or may be obtained, for a
nominal cost, from the National Technical Information Service,
5285 Port Royal Road, Springfield, Virginia 22151.
This report was furnished to the U. S. Environmental Protection
Agency by Williams Research Corporation in fulfillment of Contract
No. 68-01-0405 and has been reviewed and approved for publication by
the Environmental Protection Agency. Approval does not signify that
the contents necessarily reflect the views and policies of the agency.
The material presented in this report may be based on an extrapola-
tion of the "State-of-the-art". Each assumption must be carefully
analyzed by the reader to assure that it is acceptable for his pur-
pose. Results and conclusions should be viewed correspondingly.
Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
Publication No. EPA-460/9-73-001
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Report No. WR-ER11
Revision No. 1
SUPPLEMENT
AUTOMOTIVE GAS TURBINE
ECONOMIC ANALYSIS
INVESTMENT CAST TURBINE WHEEL
ENVIRONMENTAL PROTECTION AGENCY
ADVANCED AUTOMOTIVE POWER SYSTEMS DEVELOPMENT DIVISION
2929 PLYMOUTH ROAD
ANN ARBOR, MICHIGAN 48105
FROM
WILLIAMS RESEARCH CORPORATION
2280 W. MAPLE ROAD
WALLED LAKE, MICHIGAN 48088
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FOREWORD
THIS REPORT, NO. WR-ER11, REVISION NO. 1 ENTITLED "SUPPLE-
MENT, AUTOMOTIVE GAS TURBINE ECONOMIC ANALYSIS, INVESTMENT
CAST TURBINE WHEEL" IS SUBMITTED TO THE ENVIRONMENTAL PRO-
TECTION AGENCY, DIVISION OF ADVANCED AUTOMOTIVE POWER SYSTEMS
DEVELOPMENT. THE REPORT IS SUBMITTED PURSUANT TO CONTRACT
NO. 68-01-0405 BETWEEN THAT AGENCY AND WILLIAMS RESEARCH
CORPORATION AND IS BASED ON ALL WORK ACCOMPLISHED UNDER
THAT CONTRACT.
R. T. Hall E. E. Davenport
Project Director Director of Administration
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TABLE OF CONTENTS
Page
SUMMARY 1
INTRODUCTION 2
GENERAL PROCESS DESCRIPTION 4
Manufacturing Assumptions 5
Investment Patterns 6
Shell Molding 7
Refractory Mold Burnout, Assembly and Firing 9
Master Ingot Melting 10
Production Melting and Casting 11
Cooling, Shakeout and Cleaning 14
Finishing Operations 16
COST SUMMARY 17
Raw Materials 18
Metal Production Costs - IN713LC 18
Shell Cost Summary 20
Plant and Equipment 25
Manpower Requirement 25
Turbine Wheel Cost 45
OPTIONAL ALLOY IN-738 SUPPLEMENT 47
Optional Heat Treating 48
ACKNOWLEDGMENTS 53
ADDENDUM 1 - AUTOMATED INVESTMENT CASTING IN THE USSR 54
ADDENDUM 2 - ALLOY SUMMARIES, 713LC/IN-738 59
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SUMMARY
1. This study provides adequate evidence that volume pro-
duction of automotive turbine wheels investment cast
in nickel base alloys is both feasible and within the
current state of the art.
2. This study has generated a logical process for mass
producing investment cast turbine wheels and also pro-
vides the necessary capitalization requirement to support
such a manufacturing capability.
3. The cost analysis supports the original premise of an
80%-20% material to labor ratio. In addition the capital-
ization, manloading and resultant overhead considerations
are well within automobile industry standards.
4. The O.E.M. selling price per turbine wheel mass produced
at the projected study levels would be approximately $10.04
to $12.15 each dependent on alloy selection.
5. The capitalization of a facility to investment cast
2,000,000 turbine wheels per year would cost approximately"
$12,000,000 to $15,000,000, dependent on alloy selection.
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SECTION I
INTRODUCTION
The Automotive Gas Turbine Economic Analysis Final Report,
dated December 1972, used an existing prototype automotive
turbine engine as a baseline. This engine was analyzed
in detail for its producibility, utilizing value analysis
techniques to further refine the engine for mass production.
Manufacturing processes were studied for their applicability
to turbine engine components, and a development program
was outlined to foster process development for those areas
defined as high cost items.
One high cost area identified was that of investment castings
used in the automotive turbine engine. A specific area
of concern was the cost of investment turbine wheels after
vendor prices were obtained for production rates of 1,000,000
castings per year. These vendor prices indicated an unreasonable
proportion of labor cost to material cost.
Based on the material content of the turbine wheels, an
Automotive Original Equipment Manufacturer (OEM) selling
price of $14.00 each was developed. Some comments ensued
regarding the assumptions made to arrive at this price;
and in response to these comments, the Environmental Protection
Agency authorized a more detailed analysis of the cost of
investment castings produced in automotive quantities.
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Although current prices for investment castings in the United
States might indicate that precision parts made by this
method have no place in the automotive sector, it should
be noted that investment castings are used extensively for
automotive applications in Europe. Specific attention is
directed to the highly automated Gorky Automotive Works,
an investment foundry in Russia, which produces approximately
15,000,000 castings per year for the industry. (See addendum
#1 for details.)
A detailed description of the Gorky Operation was furnished
by Technology Associates, Inc. of Dedham, Mass.; and an
evaluation of these data definitely indicates that high-
volume , automated investment foundries can produce certain
types of investment castings at low cost. In addition,
there has been progress in the United States on the part
of several material suppliers to develop binder processes
that will reduce the time required to build investment shell
molds. A typical process; developed by the E.I.duPont Company,
trade name Colal; elimates the necessity of drying the shell
between dips.
After considering these binder developments and the advanced
automation techniques of the Gorky Foundry, it has been con-
cluded that the investment casting process may, in fact,
offer the best solution to the problem of manufacturing
turbine wheels at a cost acceptable to the automotive industry,
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For purposes of this study, a conceptual investment casting
process, suitable for volume production of automotive turbine
wheels, has been developed. This process includes the physical
and cost elements of a production facility, equipment, manpower,
raw material, and all other significant manufacturing elements
necessary to develop a meaningful unit cost for automotive
turbine wheels. This supplement to the original report presents
the details of this process and the associated cost analysis.
GENERAL PROCESS DESCRIPTION
The proposed investment casting process is based on fundamental
investment casting expertise utilizing, where applicable,
developments in fast drying binders, typical high volume
production automation and some modestly innovative production
melting techniques to produce low cost turbine wheels.
The pattern materials are polystyrene or polystyrene/wax
utilized in multi wheel assemblies. The shell making is
accomplished in an automated continuous slurry/stucco dip
system using a binder system which precludes long intermediate
drying cycles during the building steps.
Melting is carried out in two steps; the first to alloy master
heat ingots, and the second to accomplish production melting
for the final casting operation. Some innovations, as described
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in the detailed process, develop practical solutions for
shell support during the pouring operation to accommodate
heat retention and withstand the forces applied to the shell
resulting from the proposed centrifugal assist.
The finishing operations such as cleaning, inspection, cutting,
and heat treatment, use either current or modifications of
current production techniques.
For purposes of identification the following detail process
description is broken down into the basic manufacturing
techniques. These are:
Investment Pattern making
Shell making
Master heat melting
Production melting
Cooling, shakeout, and cleaning
Cutting, final inspection and shipping
In addition, the processing includes an optional heat treat
operation to support alloy IN738.
Manufacturing Assumptions
1. The refractory mold technique utilizes binder systems
which do not require intermediate drying between refractory
layers.
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2. The melting operations are carried out in two stages.
The first to produce ingot and the second the production
casting. Direct melting costs are $0.03/pound for ingot
and $0.05/pound for the production melt.
3. The system is designed to eliminate labor where practical
by use of automatic production techniques.
4. The production foundry will operate 250 days, two 8-hour
shifts, 5 days per week. Additional maintenance is
planned for furnace overhaul and system maintenance. The
primary master ingot furnace and any heat treating facili-
ties will operate 250 days, three 8-hour shifts, 5 days per
week.
5. Direct labor rates are assumed to be $7.50/hr., including
fringes.
6. Capital depreciation on all facilities except building at
12 years. Building carried 20 years.
7. General and administrative costs at 10 percent.
8. Corporate profit at 25 percent.
Investment Patterns
The first step of the detailed process concerns itself with
the manufacture of the subassembly patterns which in final
assembly will be used for building the refractory shell.
The material/s are polystyrene and/or polystyrene wax combinations,
All parts are made using high production rate injection molding
equipment.
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The turbine wheel pattern is injection molded in one piece
polystyrene using a movable segment water cooled mold. These
machines are fully automatic and in sufficient quantity to pro-
duce in excess of 640 turbine wheel patterns per hour.
The balance of the assembly such as the central runner, pouring
cup patterns etc. are molded separately. For a visual pre-
sentation of the pattern assembly see Figure 1.
After molding, the separate patterns are conveyed to an assembly
area where the components will be assembled manually using the
appropriate patterns and hooked to an overhead conveyor which
carries the assemblies to the shell molding area.
Shell Molding
The shell molding area consists of handling systems, slurry
tanks, stuccoing beds and drying areas designed to produce
110-125 mold assemblies per hour in an automated assembly
line. Supporting equipment consists of batch slurry prepara-
tion and storage tanks, and refractory preparation, separation,
reconditioning and storage equipment.
The investment pattern assemblies are delivered to the shell
building area. This area must be humidity and temperature
controlled.
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The assemblies are then dipped in a refractory slurry, re-
tracted and dipped in a fluidized bed of stuccoing sand.
The slurry coat is repeated and then alternately dipped and
stuccoed in the binder slurries until three to six coats
are built up.
After the final dip, the shell/pattern assemblies are carried
into a drying room and dried for approximately 15 hours.
The drying parameters will consist of temperature, humidity, -
and air flow control.
After the drying cycle is complete the refractory molds are
conveyed to the next operation which is pattern burnout.
Refractory Mold Burnout, Assembly and Firing
The shell/pattern assemblies are transferred from the drying
room to the burnout/firing furnace. This furnace is used
to burnout the polystyrene, fire the shell and preheat for
pouring.
Prior to firing, the shells are placed in ceramic canisters
(silicon nitride or similar) and supported with coarse refrac-
tory invested between the canister and the shell. This assembly
is then placed on the furnace conveyor and fired to achieve
the desired temperature for pouring and to assure that all
pattern residue is removed.
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These assemblies are then conveyed hot to the production
furnace line for pouring.
Master Ingot Melting
The turbine wheel alloy is melted from virgin or reverted
material or a combination of same.
The master heat is considered a separate entity on off-
line operation. This is done to allow total independence
from the production line and conversely the production line is
not directly dependent on the conversion furnace. The ingots
are stockpiled to allow a reasonable amount of downtime for
furnace repair and production melting lead.
The melting procedure involves charging, melting, alloy ad-
justment and ingot pouring in a vacuum furnace.
The master heat total is 12,000-15,000 pounds and the daily
production requirement is 35,000 pounds plus.
The furnace charge is made up in an adjacent charge room. All
materials are dry stored. The charge bucket is transferred to
the vacuum furnace and the charge is then laid in the crucible
in preparation for melting.
The ingot molds are assembled at the pouring station within the
vacuum chamber.
10
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The vacuum chamber is sealed and the operating vacuum is es-
tablished. The furnace temperature can be elevated during
pumpdown.
When the charge is molten, final alloy adjustments are made
using material already placed in a separate additive vacuum
lock. Spectrographic samples are tested for alloy balance and
when all percentages are nominal, the furnace may be poured.
The complete heat is poured into ingot molds and allowed to
solidify.
After solidification is achieved, the vacuum chamber is opened
and the molds are removed to a stripping (teardown) area.
The ingots are removed from the molds, cropped and cut into
production furnace charges of approximately 24 pounds each
and stored until needed.
An illustration of a typical ingot furnace may be found in
Figure 2.
Production Melting and Casting
The production melting line consists eight 50-pound capacity
electric induction vacuum furnaces (including two spares).
These furnaces are able to pour every 180 seconds. They are
complete with three handling locks, one to charge the furnace,
11
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FIGURE 2
MASTER HEAT INGOT FURNACE
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the second to place the mold assembly into the pouring station
and the third to remove the casting from the furnace chamber.
Self-contained manipulators, to move the shell and casting in
the vacuum chamber from and to the entry and exit locks after
vacuum is achieved, are included. Centrifugal assist is in-
corporated in the pouring table, in addition, there are
mechanical manipulators at the entry and exit locks and appro-
priate conveyors to deliver the assemblies to the separation
and shakeout equipment.
The pre-cut ingot charges are placed in a feed hopper or mag-
azine which releases a single billet charge which is transferred
into an induction coil. The charge is preheated in the in-
duction coil to approximately 2250°F in atmosphere. When temp-
erature is achieved, the billet is moved from the induction
coil through the outer door of the charging lock. The outer
door is closed, the lock pumped down and the charge pushed
from the lock into the backtilted furnace crucible.
After the furnace crucible is returned to the vertical posi-
tion the preheated charge is brought to superheat temperature
(approximately 2650°F). During this heating cycle the previous
casting (assembly) is locked out of the furnace through the
exit lock and a new shell/canister assembly is placed on the
pouring table.
13
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When the charge is at the proper superheat temperature, the
pouring sequence is initiated by tilting the furnace and
actuating the centrifugal drive. After pouring, the centrif-
ugal drive is continued until the exit lock is ready for the
next charging sequence (approximately 2 to 2-1/2 minutes).
See Figure 3 for furnace example.
Cooling, Shakeout and Cleaning
The cooling and shakeout portion of the production facility
consists of conveyors to remove all castings from the exit
locks of the production furnaces, an assembly separation
station and a shell/casting separation unit. The shell
material is returned to the refractory preparation area
to be crushed, ground and separated for reuse. The ceramic
canisters are returned to the canister preheater for reuse.
The casting assembly is mechanically positioned in the vacuum
furnace exit lock when the pouring sequence is complete. The
interlock door is closed and the vacuum is released. When
the outer exit lock door is open a mechanical manipulator
extracts the assembly and places it on a conveyor which carries
it to the assembly separation station.
At the separation station an extractor removes the casting from
the loose refactory/canister and places it on an overhead con-
veyor. At the same time an arm dumps the coarse refractory out
14
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Ul
FIGURE 3
PRODUCTION MELTING FURNACE
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of the canister. The refractory is collected mechanically and
it and the canister are returned to the shell/canister assembly
station for reuse.
The casting is moved to the cooling/shakeout unit where the
shell is completely removed by vibration and high pressure
water jets.
The castings are carried to the cleaning unit by overhead
conveyor. The refractory shell material is recovered in
coarse slurry form and is returned to the shell refractory
recycling unit.
The proposed recycling system consists of the appropriate
drying, crushing and screening equipment to process and grade
the fused silica for reuse. Some loss is anticipated and a
summary of final yield may be seen on Page 24 of this report,
The cleaning operation consists of light etching and hot
water rinsing the castings and is a continuation of the
shakeout production line.
Finishing Operations
The castings are conveyed to a line of cutoff machines which
should be designed to automatically restrain, index and cut off
(by friction saws) the individual turbine wheels from the as-
cast stack. The wheels drop on a soft conveyor and are sep-
16
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arated from the sprue which is returned to the charge room
for remelt. The turbine wheels are dimensionally checked by
an automatic gaging system.
After inspection, the wheels are packaged, using individual
containers.
COST SUMMARY
The turbine wheel production level which established this cost
analysis is two million units per year. This being based on
two wheels per engine and the original economic analysis based
on a production commitment of one million engines per year.
The Foundry operation to produce this quantity of wheels is
based on 250 operating days and two 8-hour shifts. The excep-
tion to this is the ingot furnace which would operate on a
three shift basis. This will produce a minimum of 630 wheels
per hour including an estimated 5% scrap.
To evaluate costs the following primary cost centers were
developed:
1. Raw Materials
2. Plant & Equipment Capitalization
3. Manpower (Direct Labor)
4. Overhead, Administrative Fees and Profit
17
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Within each of those cost centers detailed breakdowns are
shown and appropriate tables are referenced as applicable.
Raw Materials
The first primary cost center which was considered is the
cost of raw materials; the various metallic constituents
making up the ingot charge, the refractory system for shells
including binder and wax/plastic pattern material.
Metal Production Costs - IN713LC
Nickel base alloy IN-713LC was used for pricing in the original
automotive turbine engine study. This alloy is currently used
in the prototype engine.
The casting characteristics of the alloy support the primary
considerations of the manufacturing processes previously
described.
The cost of the alloy is evaluated using the sum total of the
required constituents of the alloy in forms that are compatible
with normal vacuum melting practices. A summary of the con-
stituents, charge form and costs is found on Table I. The
nominal current price per pound is $1.61. In addition
$0.05/pound was added for melting cost at the ingot furnace.
A summary of annual ingot costs may be found on Table II.
18
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TABLE I
MASTER HEAT-VIRGIN MATERIAL COST -
ELEMENT
C
Cr
Ni
Mo
Cb/Ta
Ti
Al
B
Zr
Price Per Lb.
%
0.05
12.50
74.00
4.20
2.20
0.80
6.10
0.01
0.10
= $3218.69
FORM
Powder
Electrolytic
Electrolytic
Pellet
Cb/Ta
Sheet Scrap
Sponge
Pig
Ni/B
Sponge
= $1.61 Ib.
COST/LB. ($)
0.50
1.15
1.53
3.70
6.63
1.37
0.28
3.25
3.52
IN713 LC
WT./TON (LB.)
1.0
250.0
1480.0
84.0
44.0
16.0
122.0
0.2
2.0
1999.2
COST/TON ($)
0.50
287.50
2260.00
310.80
291.72
21.92
34.16
0.65
7.04
3218.69
1999.2 Ib.
$1.61 Ib.
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Included in the above costs were the following manufacturing
assumptions:
1. Scrap - 5%
Sprue Returns - 30%
2. Total Metal Loss
Cutting Loss 3%
Oxidation, Vaporization 5%
Spillage 2%
3. The per pound melting cost of $0.05/pound includes
electrical power, coolant water, crucible repair
and replacement and mold repair and replacement.
Using these assumptions the annual ingot production is shown
on Table II and the final cost is $1.89 per pound which
includes the primary ingot melting factor of $0.03/pound.
Shell Cost Summary
The shell building process was slightly more complex to analyze,
The wax plastic system worked out to cost $.03 per wheel or
about $0.01 per pound of metal and this is used for the purpose
of pricing in this analysis.
To develop the amount of binder/refractory which would be used
per pound of casting the following assumptions were made:
Volume of a typical (6) wheel stack investment shell:
20
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TABLE II
ANNUAL INGOT PRODUCTION-COST SUMMARY
ALLOY IN713LC
Description
Wgt/Annual/lbs,
Melt Cost/lb.
Metal Cost/lb,
Required Wgt.
5,400,000
ANNUAL INGOT COST-POUND
$1.89**
Annual Cost Total
Required Delivered
Product
Revert Metal
Total Metal
Loss
Virgin Metal
5,400
1,890
727
6,127
,000
,000
,000
,000
$0
0
0
0
.03
.08*
.03
.03
$1
.61
Transfer
1
1
.61
.61
$8,856
151
1,192
10,048
,000
,200
,280
,280
.00
.00
.00
.00
$10,199,480.00
* Includes Reprocessing Cost + Melt Cost
** Includes Average Cost of Delivered Product, Revert Metal and Total Metal Loss Replacement
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The wheel O.D. is approximately 5", and the irregular form
measures 27.5" long. By assuming a V thick shell buildup
the volumetric relationship of the simple cylinder is:
AO = AX x L = Volume
Where A0 = 25.97 m2
and AI = 21.65 in2
and L = 27.5"
The volume therefore is 129.6 in3.
If this volume is then considered as essentially dry fused
silica (after drying) at a density of 100 lb/ft3 or 0.0507 lb/in3
the weight of cylinder A0 - AI x L = 6.57 Ib. This weight of
formed refractory shell is sufficient to produce a 22-23 pound
turbine wheel assembly.
The constituents of the shell system less the pattern material
were then developed in portional weights as follows:
Proportional Weight of Slurries (Est.):
2 Prime Coats M-l 0.57 Lbs.
3 Backup Coats M-2 3.00 Ibs.
3 Backup Coats P-2 3.00 Ibs.
Total Weight 6.57 Ibs.
22
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Thus the price breakdown of the entire refractory system is
as follows:
Price Breakdown by Weight:
Colal M-l
25 Ibs. Colal M @ .23/lb.
17.7 Ibs. H20 <§ .001/lb.
.02 Ibs. Antarox BL240
100 Ibs. Fused Silica @ .18/lb.
Dry Shell per CWT
Or
$ 5.750
0.020
0.006
18.000
$23.776
$ .238/lb,
Colal M-2
32 Ibs. of Colal M @ .23/lb.
100 Ibs. of Fused Silica @ .18/lb.
Dry Shell per CWT
Or
Colal P-2
35 Ibs. of Colal P @ .36/lb.
100 Ibs. of Fused Silica @ .18/lb.
Dry Shell per CWT
or
Gross Shell Cost:
0.57 Ibs. M-l @ $0.238/lb.
3.00 Ibs. M-2 @ $0.254/lb.
3.00 Ibs. P-2 @ $0.306/lb.
Gross Total
$0.136
0.762
0.918
$1.816
$ 7.36
18.00
$25.36
$ 0.254/lb.
$12.60
18.00
$30.60
$ .306/lb,
23
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The manufacturing process is developed to recover part of the
refractory used in the shells and the following assumptions
were used:
1. The solids composed of various mesh sizes of fused
silica can be recovered at $0.005/lb. plus capitali-
zation expense.
2. The recovery percentage will be 90% minus 5% opera-
tional loss or a net recovery of 85% of all fused
silica used in the process.
A shell with a dry weight of 6.57 Ibs.
with 85% net recovery and a $0.005/lb.
processing cost will be:
6.57 Ibs.
x $ .18
$1.183
less 15% 0.175
$1.008
Less $.005/lb. 0.033
Process $0.975 net recovery
By subtracting the net recovery from the gross refractory cost
per shell the following refractory cost is developed.
Gross Material Cost:
$1.816
Net Recovery Return 0.975
Net Mat'l. Cost Per Shell $0.841
Cost Per Turbine Wheel:
$0.841 4 6 = $0.14
Cost Per Ib. of Cast Metal (Useable)
Wheel =2.7 Ibs. $ .0506/lb.
24
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Finally for storage requirements the following monthly inventory
will be required: Annual use/cost relationships may be found in
Table III.
Binders 95,190 Pounds
Silica (Fused) 170,000 Pounds
Wetting Agent 3,350 Pounds
Plant & Equipment
The second major cost center to discuss is plant and equipment
capitalization.
The plant was laid out in rudimentary form (Figure 4), and
then basic pricing was applied on a blanket basis per Mid-
western area construction and approximate land costs (Table III
Page 40) .
The equipment called out in the facilities Summary Sheets
(Table III, Page 27 thru 40) are based on supplier infor-
mation. However, portions of the transfer systems were
estimated by Williams Research Corporation Facilities
Engineering. A grand total of facilities may be found on
Table III Page 27.
Manpower Requirement
The third primary cost center is the manpower requirement.
Using the operating assumptions, the manpower allocations
are broken down by shift operations, and three categories
of labor; direct hourly, indirect hourly and salary. These
individual analyses are shown on Table IV, Pages 41 thru 44.
25
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CHARGE ROOM
MOLD STRIPPER
STATION
FURNACE REPAIR
INGOT CUTOF
GS
nrn! Iron
^ PATTERN SHOP
O
i
^SHIPPING AND RECEIVING
METALLURGICAL
LABORATORY
u u .
MAINTAINENCE
o
o
o
o
o
o
o
QSHELL PREPARATION
ooo
DRYING ROOM
PRODUCTION CASTING FURNACES
ITANNISTER /
SHELL
_ J
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nnnna
DODDD
DDDDD
BURNOUT AND FIRING FURNACES
GENERAL OFFICES
to
TURBINE WHEEL FOUNDRY
FIGURE 4
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TABLE III SUMMARY
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
A
B
C
D
E
F
G
H
I
J
K
L
Description & Reference
Pattern Making - Plastic
Shell Making
Dewax, Firing/Preheat Area
Ingot Melt Facility
Production Melting & Casting
Facility
Cooling, Shakeout & Cleaning
Finishing Facility
Shipping
Maintenance
Laboratories
Miscellaneous
Building & Grounds
Est. Cost Elec.
Unit Est. Cost Foundations & Erection Total HP or KVA
$ 823,500
1,180,000
559,000
1,823,000
2,185,000
384,000
1,386,000
169,500
55,000
355,000
105,000
2,304,000
Sub Total $13,329,000
15% Engr. & Cont. 1,699,350
$]3,028,350
M
Heat Treat Alloy In-738
tv)
Incl 15% Engr. & Cont. 2,473,075
GRAND TOTAL (INCLUDING HEAT TREAT OPTION) $15,501,425
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
A
A-l
A-2
A- 3
A- 4
A-5
A-6
A- 7
A- 8
Description & Reference Unit
Pattern Making - Plastic
Plastic Injection Mold 8
Machines
Plastic Storage & Delivery 1
System
Soft Conveyor 100 Ft. @ 75
Blade/Ring Dies (Molds) 8
Nut & Pouring Cup - Dies/Molds 3
Room Atmosphere
Die Repair, Etc. (incl. B sec.) 1
Ass'y Tube
Est. Cost
Est. Cost Foundations & Erection Total
$30,000
17,500
7,500
50,000
10,000
30,000
15,000
12,000
$7,500 $300,000
8,000 25,000
7,500
400,000
30,000
4,000 34,000
15,000
12,000
Elec.
HP or KVA
40 KVA
100 HP
5 HP
15 HP
50 HP
30 HP
50 HP
$823.500
* Incl. Installation
00
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
B
B-l
B-2
B-3
B-4
B-5
B-6
B-7
Description & Reference
Shell Making
Refractory Reconditioning
Batch Slurry Make-up System
Production Slurry Tanks
Drying Room Conveyor
Dip Manipulator Machines
Binder Storage
Drying Facility
Unit Est.
1 $250
40
70
100
16 25
75
50
Est. Cost
Cost Foundations & Erection Total
,000
,000
,000
,000
,000
,000
,000
$35,000 $285
20,000 60
30,000 100
40,000 140
60,000 460
75
10,000 60
.OOC
,000
,000
,000
,000
,000
,000
Elec.
HP or KVA
250
50
100
50
160
75
50
H
H
H
H
II
H
H
.P.
.P.
.P.
.P.
.P.
.P.
.P.
$1,180,000
* Incl. Installation
to
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
C
C-5
C-6
C-7
C-8
C-9
C-10
Description & Reference Unit Est.
Dewax, Firing/Preheat Area
Firing & Preheat System
Cannister Preheat
Backup Sand Preheat
Shell/Cannister Backup Sand
Assembly Unit
Cannister Manipulator
Master Operator Console
$175
75
60
50
30
75
Cost Foundations &
,000
,000
,000
,000
,000
,000
$40
7
7
15
5
30
Est. Cost
Erection Total
,000
,000
,000
,000
,000
,000
$205
82
67
65
35
105
,000
,000
,000
,000
,000
,000
Elec.
HP or KVA
50
25
25
15
10
5
H.P.
H.P.
H.P.
H.P.
H.P.
H.P.
$559,000
Incl. Installation
to
o
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
D
D-l
D-2
D-3
D-4
D-5
D-6
D-7
D-8
Description & Reference Unit
Ingot Melt Facility
12,000 - 15,000 Ingot Melt
Furnace Including Vacuum
System
Mold Stripping Station
Crucible Assembly
20-Ton Crane
Charge System
Cutoff & Cropping Machines 4
Walking Beam Table
(Ingot transfer)
Ingot Molds & Misc. Equip
Est. Cost Foundations & Erection
$1,100,000
50,000
50,000
125,000
80,000
10,000
30,000
100,000
$100,000
30,000
20,000
40,000
40,000
2,000
10,000
Est. Cost Elec.
Total HP or KVA
$1,200
80
70
165
120
48
40
100
,000 1200 KVA
=100 KVA*
,000 50 H.P.
,000
,000 35 H.P.
,000 100 H.P.
,000 40 H.P.
,000 15 H.P.
,000
$1,823,000
* 1200 KVA Main Power; 500 KVA Auxiliary Equipment
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item Description & Reference
Est. Cost
Unit Est. Cost Foundations & Erection Total
Elec.
HP or KVA
E Production Melting & Casting
Facility
E-l Induction Vacuum
Furnaces (50-lb.)
E-2 Preheat Induction Coils
E-3 Master Control Room
E-4 10-Ton Overhead Crane
E-5 Inject. & Extract.
Cannister Assembly
Manipulators
E-6 Hopper/Magazine (6) & Charging
Devices
12
$125,000 ea.
25,000 ea,
250,000
95,000
25,000 ea.
60,000
$20,000 ea. $1,160,000
15,000
75,000
1440 KVA*
30
50
15
5
,000
,000
,000
,000
180
300
110
360
,000
,000
,000
,000
300
20
25
180
KVA
H.P.
H.P.
H.P.
30 H.P.
* Includes power and auxiliary equipment
$2,185,000
to
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
F
F-l
F-2
F-3
F-4
F-5
F-6
Description & Reference . Unit
Cooling, Shakeout & Cleaning
Facility
Cooling Tunnel
Dumping Manipulator
Cannister Return System
Sand Return System
Shakeout & Water Jet System
Cleaning System
Est. Cost Elec.
Est. Cost Foundations & Erection Total HP or KVA
$ 40,000 $12,000 $ 52,000 25 H.P.
35,000 10,000 45,000 15 H.P.
30,000 10,000 40,000 10 H.P.
20,000 12,000 32,000 20 H.P.
100,000 40,000 140,000 50 H.P.
60,000 15,000 75.000 50 H.P.
$384,000
OJ
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item Description & Reference
Est. Cost
Unit Est. Cost Foundations & Erection Total
Elec.
HP or KVA
G Finishing Facility
G-l Cutoff Units
G-2 Cleaning System
G-3 Final Inspection Station
G-4 Automatic Packaging Unit
$ 50,000 ea.
50,000
950,000
75,000
$12,000
14,000
75,000
10,000
$212,000
64,000
1,025,000
85,000
120 H.P,
25 H.P,
5 H.P,
25 H.P,
$1,386,000
OJ
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item Description & Reference
H Shipping
H-l Container Packaging Unit
H-2 Platform Scales
H-3 Lift Truck
H-4 Levelators
H-5 5-Ton Overhead Crane
Est. Cost Elec.
Unit Est. Cost Foundations & Erection Total HP or KVA
$25,000 $10,000 $ 35,000 10 H.P.
2 5,000 ea. 2,000 12,000
2 8,000 — 16,000
2 12,000 7,500 31,500
75,000 — 75,000 10 H.P.
$169,500
OJ
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item Description & Reference
Est. Cost Elec.
Unit Est. Cost Foundations & Erection Total HP or KVA
I Maintenance
1-1 Miscellaneous Equipment
$50,000
$5,000
$55,000 250 HP
u>
en
$.55,000
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
J
J-l
J-2
J-3
Description & Reference
Laboratories
Sand
Slurry
Metallurgical
Est. Cost Elec.
Unit Est. Cost Foundations & Erection Total HP or KVA
50 H.P.
$ 30,000 — $ 30,000
40,000 — 40.000
275,000 $10,000 ,000
$355,000
co
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item Description & Reference
Unit Est. Cost
Foundations & Erection
Est. Cost
Total
Elec.
HP or KVA
K Miscellaneous
K-l Offices & Furniture
K-2 Cafeteria
K-3 Shop Offices
$60,000
25,000
20,000
$60,000
25,000
20,000
$105,000
U)
CO
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
Item
L
L-l
L-2
L-3
Description & Reference
Building & Grounds
Building
Land
Parking, Misc. Grounds
Est. Cost
Unit Est. Cost Foundations & Erection Total
60,000 ft2 $2,104,000
10 Acres 100 ,000
100,000
Elec.
HP or KVA
Total
$2,304,000
OJ
vo
-------
TABLE III (cont'd.)
TURBINE WHEEL FOUNDRY
ESTIMATED COST OF FACILITIES
TO HEAT TREAT IN-738 ALLOY
Item
M
M-l
M-2
M-3
M-4
M-5
M-6
M-7
Description & Reference Unit Est. Cost
Heat Treatment Facility
Four 3-Chamber Vacuum $190,000
Batch Furnaces
Four Continuous Exothermic 150,000
Furnaces
One 5 -Ton Overhead Crane 75,000
Miscellaneous Cold Conveyor 2,500
50 ft.
Miscellaneous Hot Conveyor 10,000
100 ft.
Building 20,000 ft2
Grounds 2.0 Acres
Est. Cost Elec.
Foundations & Erection Total HP or KVA
$35,000 $ 900,000 400 KVA
35,000 440,000 350 KVA
100 H.P.
Comp. 75,000 10 H.P.
1,000 3,500 10 H.P.
2,000 12,000 10 H.P.
700,000
20,000
Sub Total $2,150,500
^, 15% Engr. & Cont. 322,575
TOTAL $2,473,075
-------
TABLE IV
MANPOWER SUMMARY
TOTALS BY SHIFT
Alloy IN713LC
Direct Hourly
Indirect Hourly
Salary
TOTAL
Alloy IN-738
Direct Hourly
Indirect Hourly
Salary
1
25
19
ii
62
29
19
18
Shift
2_
22
16
_5
43
26
16
5
3_
5
9
_4
18
5
9
4
Total
52
44
27
123
60
44
27
TOTAL
66
47
18
131
41
-------
TABLE IV (cont'd.)
MANPOWER
Shifts
Pattern Making
Plastic Mold Operator
Pattern Assembly Area
Sub Total
Shell Material Prep, and Shell
Batch Slurry Operator
Refractory Reconditioning
Operator (Sand Lab)
Production Line Operator
Dip and Stucco
Inspection
Sub Total
Shell Drying Burnout & Fire
Burn Out Furnace Operator
Burn Out Furnace Laborer
Sub Total
Master Melting Operation
Furnace Crew
Mold Teardown and Assembly
Technician
Sub Total
Production Melting and Casting
Master Furnace Operator
Furnace Helpers
Sub Total
Cooling and Shakeout
Operator
Laborer
Sub Total
I
3
1
T
Building
1
1
1
1
4
1
1
2
3
1
1
5~
1
2
3
1
1
2
2_
3
1
I
0
0
1
1
2"
1
1
2
3
1
1
5~
1
2
3
1
1
2~
3_
0
0
0
0
0
0
o
o"
0
0
0
3
1
1
5"
0
0
0
0
o
o"
Total
6
2
*
1
1
2
2
6
2
2
I
9
3
3
15
2
4
6
2
2
4
42
-------
TABLE IV (cont'd.)
Shifts
Total
Finishing
Cutoff Machine Operators
Inspection
Packaging
Shipping
Sub Total
TOTAL
2
1
1
1
5
25
2
1
1
0
0
0
0
0
22
4
2
2
1
~9
52
Cleaning and Heat Treatment (Optional-Use with IN-738 Alloy Only)
Helper
Maintenance
Melting
Production Furnace
Miscellaneous
Met. Lab. a
Quality Control
Foundry Clerk
Production Clerk
Relief
Truck Operators
Nurse
Stores
Shipping
: Operator
Sub Total
MISCELLANEOUS
2 2
2 2
4 4
MANPOWER
2
2
4
Shifts
•nace
md Shell Room
die repair)
Sub Total
Sand Lab.
.1
irk
•s
Sub Total
:L
1
1
2
4
F
1
2
1
1
2
1
1
1
1
IT
2_
1
1
2
3
7
1
2
1
0
2
1
1
1
0
9
3_
3
3
0
2
*
1
0
0
0
0
0
0
0
0
1
6
6
12
Total
5
5
4
9
2T
3
4
2
1
4
2
2
2
1
IT
TOTAL
T9
~9
43
-------
TABLE IV (cont'd.)
SUPERVISION
Shifts
Total
Manager
Production Superintendent
General Foreman
Metallurgist
Chemist
Plant Engineer
Maintenance Superintendent
Maintenance Foreman
Production Foreman
Draftsman
Personnel/IR
Accounting
Secretary
Inventory
Security
Sub Total
1
1
1
1
1
1
1
1
3
1
1
1
1
1
2
TF
0
0
0
0
0
0
0
1
3
0
0
0
0
0
1
5
0
0
0
0
0
0
0
1 .
2
0
0
0
0
0
1
•3
1
1
1
1
1
1
1
3
8
1
1
1
1
1
4
2T
TOTAL
18"
44
-------
Turbine Wheel Cost
The following is the summary of costs and resultant per wheel
cost:
Alloy Cost - Ingot = $1.89/pound
Pattern, Shell &
Production Melt Cost* = $0.13/pound
= $2.02/pound
Material Cost per Wheel = 2.7 Ibs x $2.02/lh
= $5.45
The direct annual labor costs are as follows:
52 men x 2080 hr./year
x $7.50 (includes 50%
fringe benefits) = $811,200.00
Therefore the direct labor cost to produce 2,000,000 turbine
wheels per year is $0.41 per wheel.
The overhead for the production of the 2,000,000 wheels annually
consists of indirect labor (hourly and salary) and capital
equipment building and grounds as follows:
*Total of $0.03 Polystyrene/wax patterns, $0.05 for refractory
shell and $0.05 for melting costs (includes power, water &
crucible refractory, etc.) in the production furnace.
45
-------
1. Capitalization & Depreciation Schedule Annual
a. Equipment (12 years)
$10,378,750 T 12 $ 864,896.00
b. Building and Grounds (20 years)
$2,649,600 T 20 $ 132,480.00
2. Labor, Indirect
a. Hourly
44 men x 2080 hr/year x 7.50 $ 686,400.00
b. Salary
27 men x 2080 hr/year x 7.50 $ 421,200.00
3. Miscellaneous Expenses
a. Shipping, packaging & supplies $ 100,000.00
b. Telephone, etc. 14,400.00
c. Lease Equip., Professional Services, etc. 19,200.00
d. General Maintainence 195,500.00
e. General Utilities, etc. 208,500.00
f. Property Insurance, Taxes
and Related Items 200,000.00
TOTAL $ 737,600.00
Thus the annual overhead dollar total is $2,842,576.00 (Incl.
items 1,2 & 3). The overhead percentage is therefore
$2,842,576.00 .
811,200.00
With a direct labor cost of $0.41 per wheel the labor cost per
wheel including overhead is $0.41+(0.41 X 3.50)=$1.85. Adding
material to this ($5.45 + $1.85) the final cost is $7.30.
To this cost, utilizing the original manufacturing assumptions
of 10 percent for General and Administrative costs and 25 percent
for corporate profit.
$7.30 x 1.10 = $8.03
then $8.03 x 1.25 = $10.04
the final O.E.M. selling price per wheel is $10.04 each.
46
-------
OPTIONAL ALLOY IN-738 SUPPLEMENT
This supplement to the study was initiated to include the
cost impact of substituting alloy IN-738 for IN-713LC as
the primary casting alloy for automotive turbine wheels.
This alloy is currently reaching production status in aircraft
turbine wheels due to its characteristic improvements in
elevated temperature properties. This alloy is a vacuum cast,
precipitation hardened, nickel base alloy, with excellent
high temperature mechanical properties coupled with hot
corrosion resistance. A complete summary of both alloy systems
may be found in addendum #2.
The fabrication characteristics of the alloy indicate that it
would not present substantially different casting problems than
would IN-713LC. There are two primary cost areas that would,
however, have an influence on the final price structure, these
are higher alloy constituent costs and an additional heat treat-
ment operation.
The additions to the process requirements are described as
follows:
47
-------
Optional Heat Treating (Required with IN-738 Alloy)
The heat treatment of the castings will be carried out using
current heat material procedures automated where applicable to
lower labor costs. Any heat treatment will be carried out in
assembly and before the cutoff operation.
The precipitation treatment will be carried out in a horizon-
tal vacuum furnace with multiple chambers to be able to keep
the high temperature zone in constant operation.
The castings will be stacked in batches in an appropriate con-
figuration and loaded in the entry lock adjacent to the heating
chamber. After the vacuum is balanced with the heating chamber,
the inner door will open and the batch charged into the heat-
ing chamber. The batch will be precipitation hardened for
two hours at 2050°F and when the cycle is complete, moved to
the cooling chamber and cooled to approximately 1000°F.
The batch is then charged into an aging furnace (either
a batch or continuous unit) and will be aged for a minimum
of 12 hours at 1550°F. This furnace/s is intended to be an
standard atmosphere unit, however, exothermic generator gas
can be used if oxidation would be a problem. After the aging
cycle is complete, the batch is allowed to air cool, prefer-
ably accelerated using a cooling tunnel of forced air.
The castings are then removed from the batch racks and trans-
ferred on a soft conveyor to the cutting lines.
To accomplish the above described heat treat operation additional
manpower would be required. The manpower relationships are
summarized on page 48.
48
-------
The alloy constituent summary and resultant raw materials costs
are shown on Table V. These costs are represented on Table VI
for annual requirements and the per pound cost for master ingot
therefore is $2.41 per pound. In addition using the developed
prices of the IN-713LC for shell, production melting and pattern
at an additional $0.13/lb. The Raw material cost is $2.54 per
pound or $6.86 per wheel.
The annual overhead for this supplement develops as follows:
1. Annual Depreciation-Equipment $ 971,752.00
2. Annual Depreciation- 173,.850.00
3. Indirect Labor 686,400.00
4. Misc. Expense * 737,600.00
5. Salary 421,300.00
$2,990,902.00
The direct labor annual cost is $936,000.00. Thus the
overhead rate develops at 319.5%.
* See Misc. Expense Page 46
The above figures reflect the total dollar outlay per annum to
produce 2,000,000 turbine wheels in IN738.
The direct labor cost therefore is:
$936,000.00 T 2,000,000 wheels or $ .468 per wheel.
49
-------
The direct labor plus overhead rate therefore is projected
as:
.486 + (.468 X 3.195)= $1,98 per wheel or
a labor material ratio of approximately 3:1
Therefore using the previous G&A figure of 10%, and profit
of 25% the selling price per wheel develops as:
Material $6.86
Labor 1.98
Total $8.84
Plus G&A $8.84 x 1.10 = $9.72
Plus Profit $9.72 x 1.25 = $12.15
The O.E.M. selling price for IN-738 turbine wheels is therefore
$12.15 each.
50
-------
TABLE V
MASTER HEAT-VIRGIN MATERIAL COST-IN738
Element
C
Cr
Mo
Al
Ti
Zr
W
B
Co
Ta
Cb
Mn
S
Ni
Price Per Lb.
.15
16.00
1.75
3.40
3.40
0.10
2.60
0.10
0.85
1.75
8.50
0.20
.01
62.20
$4189.52
2020 Lb.
Form
Powder
Electronic
Pellet
Pig
Sponge /Scrap
Ni/Zr (70%)
Pellet
Ni/B (18%B)
Electrolytic
Sheet/Scrap
Ni/Cb (50%)
Pellet/Scrap
-
Electrolytic
or Carbonyl
Pellet
— C*5 fi "7 A T V\
— y Z , U / *4 JjD »
Cost/Lb./$
.50
1.15
3.70
0.28
1.37
3.52
5.85
3.25
2.35
10.50
6.51
4.00
-
1.53
Wt . /Ton/Lb .
3.0
320.0
35.0
68.0
68.0
2.0
52.0
2.0
17.0
35.0
170.0*
4.0
-
1131.0**
(113) **
2020.0
Cost/Ton/$
1.50
368.00
129.50
19.04
93.16
7.04
304.20
6.50
39.95
367.50
1106-70
16.00
-
1730.43**
4189.52
01 *Yields 170 Ibs. of Cb @ 60% Cb/40% Ni. Ni weight transferred to Ni requirement at no cost.
I--
**Includes 113 Ibs. of transferred Nickel from Cb/Ni alloy.
-------
Required Wgt.
TABLE VI
ANNUAL INGOT PRODUCTION-COST SUMMARY
ALLOY IN-738
Description
Required Del.
Product
Revert Metal
Total Metal
Loss
Virgin Metal
Wgt/Annual/lbs .
5,400
1,890
727
6,127
,000
,000
,000
,000
Melt Cost/lb.
$0.03
0.08*
0*03
•0.03
Metal Cost/lb.
$2
.07
Transfer
2
2
.08
.07
Annual
$11,340
151
1,526
12,866
Cost
,000.
,200.
,700.
,700.
Total
00
00
00
00
ANNUAL INGOT COST-POUND-IN-738
5,400,000
2.41**
$13,017,900.00
* Includes Reprocessing Cost + Melting Cost.
** Includes Average Cost for Delivered product, Revert Metal and Total Melt Loss Replacement
tn
-------
ACKNOWLEDGMENTS
Williams Research Corporation wishes to acknowledge the following
contributing firms who provided us with realistic pricing and
technical assistance in their respective areas of the proposed
manufacturing process.
Foundry Magazine
Penton Plaza
Cleveland, Ohio 44114
I. E. Dupont DeNemours & Company
Technical Services Laboratory
Chestnut Run
Wilmington, Delaware 19898
Inductotherm Corporation
10 Indel Avenue
Rancocas, New Jersey 08073
International Nickel Company, Inc.
67 Wall Street
New York, New York 10005
Lindberg
Division Sola Basic Industries
2450 W. Hubbard Street
Chicago, Illinois 60612
Technology Associates, Inc.
850 Providence Highway
Dedham, Massachusetts 02026
53
-------
ADDENDUM 1
AUTOMATED INVESTMENT CASTING
IN THE USSR
FOUNDRY MAGAZINE
August 1972
54
-------
Automated
Investment Casting
in the USSR
FOREIGN FOUNDRIES a series
Soviet development of automated investment
casting is highly advanced. In one automotive
investment foundry, 80% of all operations are
automated, including pattern material preparation,
slurry preparation, patternmaking, ceramic mold-
making, dewaxing, firing of shells, embedding the
shells in backup sand, pouring, cooling, cleaning,
and cutoff. As a result of automation like this,
up to 1,000 investment cast parts are used in
automotive applications.
• THE SCOPE of application of in-
vestment casting in the USSR is
wide, particularly in producing
parts for automobiles, tractors, air-
planes, sewing machines, bicycles,
and motorcycles. In the automobile
industry alone, as many as 1,000
types of castings are produced by
investment casting, many having
been switched from drop forging,
stamping, or welding.
In 1967, the Gorky Automobile
works established an automated
investment casting foundry incor-
porating two production lines. See
Fig. 1. Each line can produce 500,-
000 molds per year in a two-shift
operation—or about 2,500 metric
tons of castings annually per line.
Typical castings produced are
shown in Fig. 2.
Eighty percent of all operations
are automated. Through use of new
technology, plus automation, the
moldmaking - casting production
cycle has been reduced from 60-70
hr to 24 hr.
Pattern Materials — To reduce
pattern shrinkage, pattern material
is melted and saturated with air to
convert it into an easy-flowing,
compressible paste. The micro-
sized air bubbles forced into the
melted material and later injected
into a die cavity offset the natural
shrinkage of the material. The
process is applicable to any formu-
lation with dripping point up to
80C (176F).
Pattern material melted out of
molds with hot water is separated
easily from the water, due to its
different specific gravity, and
pumped to the melting unit. It is
heated with hot water circulating
through piping in its walls and
bottom. Return pattern material
enters a first compartment where
any remaining water and con-
taminants settle out. Clean pattern
material passes over into a second
compartment where it is stirred to
prevent separation of constituents
and to mix in fresh ingredients.
Makeup material is melted in a
steam-heated tank and filtered be-
fore it is added.
From the melting unit, molten
pattern material is pumped through
a heated pipeline to storage tanks.
Pumping is controlled automatical-
ly to maintain material at preset
levels. In the storage tanks, the
pattern material is cooled to the
required temperature and flows by
gravity through a heated pipe into
the paste preparation unit.
There the required amount of
air is mixed into the pattern
material prior to delivery by pneu-
matic pumps through heated pipe-
lines to the patternmaking ma-
chines. Temperature is controlled
to within 1 degree C (less than 2
degrees F).
As shown in Fig. 1, four prepara-
tion units serve eight patternmaking
machines. The preparation, heating,
and pumping units are serviced by
a single operator who prepares the
equipment for operation, controls
the machinery, and monitors proc-
ess parameters.
Automated Patternmaking — Ro-
tary 10-station machines (Fig. 3)
produce patterns automatically
SOVIETS TO
LICENSE TECHNOLOGY
The Soviets believe their technology
for investment casting is advanced, and
they are willing to work with American
firms to establish similar investment
casting production facilities in the U. S.
Technology Associates Inc., Dedham,
Mass., a technology transfer consulting
firm, is handling the project in the U. S.
with injection cycles of 10, 15, or
20 sec, depending on pattern di-
mensions and the required cooling
time. The injection die is filled
under pressure at Station 1. The
die then is advanced to Stations 2
through 7 to cool the pattern. At
Station 8, the die opens and the
pattern is pushed out into a water
conveyor, which also serves to cool
the material further.
At Station 9, the die cavity is
cleaned and lubricated, and at 10
it is closed. All operations are in-
terlocked, and the drive is stopped
automatically if a malfunction oc-
curs. The dies are cooled with cold
water circulated through channels
in both halves of the dies.
Patterns are produced in a
cluster around a central hub. When
the clusters are assembled into
pattern trees, the hubs make up
the pattern for the central runner,
as shown in Fig. 4. Adoption of
standard elements in the running
system provides for easy change-
over from one type of casting to
another. Up to 10 different patterns
can be produced simultaneously.
Each injection machine is
manned by an operator. The opera-
tor cleans and lubricates the injec-
55
-------
lion molds as needed.
Size of the automatic injection
die is 240 x 240 mm (9.4 x 9.4 in.).
Usable pattern cluster diameter is
about 220 mm (about 8.5 in.). The
closing stroke is 170 mm (6.7 in.).
Cycle time depends on the size of
the casting, with 10 sec typically
used for castings weighing up to
70 g (2.5 oz) and 15 sec for cast-
ings weighing more than 70 g.
Thus output per machine is 360
clusters per hour for the 10-sec
cycle; 240 for the 15-sec cycle.
Time required for readjustment to
a new type pattern is 25-30 min.
As noted, the pattern cluster is
discharged into a water conveyor,
which carries it to the assembly
area. A pouring basin pattern first
is put on a holder attached to a
conveyor chain. Then the several
clusters are added with the aid of
a holding jig. The assembled set is
locked on the holder with a metal
cap that is coated with pattern
composition. Two workers as-
semble patterns in a temperature-
controlled room.
Slurry Production — Preparation
of the slurry, under supervision of
one operator, begins with the
automatic metering and mixing of
Fig. I—Two automated investment casting lines are operating at the Gorky
Automobile Works. The first production line, bottom of layout, was placed in
a former machine shop. Second line was installed later.
Fig. 2—Typical Soviet investment castings. Rocker arm casting, lower left, is about
Sin. long.
56
-------
Fig. 3-Rotary 10-
station machine pro-
duces patterns auto-
matically. When
necessary, all 10 dies
can be different. Die
changing time is
about V} hr.
Fig. 4-Standardized
pattern assembly
shows the riser (1),
basin (2), pattern
clusters on central
hubs (3). and the
metal cap that locks
the assembly on the
holder (4).
L
- 350 MM-H3.H m-l -
- — 488 MM H9.2 in.) -
- I
Fig. 5-Main sections of the automatic
system for making shell molds are the
automatic coating and sprinkling ma-
chine (1), drying chamber (2), bath for
melting out pattern material (3), and
the conveyor (4) that ties the
system together.
ethyl silicate and acidulated water
in a small tank. From there the
hydrolyzed silicate is dispensed
into the main mixing tank. Quartz
powder is fed into this tank by an
automatic weighing feeder belt.
The ingredients are mixed vigor-
ously, and finished slurry is de-
livered continuously through an
overflow pipe at the rate of 180 kg
(400 Ib) per hour. The system also
permits batch operation when
needed. Prepared slurry is dis-
pensed into storage tanks, then
delivered to the dip-coating baths,
where the proper level is main-
tained automatically.
Shell Molding—Slurry in the dip-
coating bath is stirred continuously
to prevent settling of solid mate-
rials.
Assembled pattern trees are
delivered by conveyor to the first
dip-coating and stuccoing unit
(Fig. 5). After the assembly has
been dipped into the slurry, it
passes under a curtain of sand and
into a drying chamber where the
slurry-stucco coating is dried in
air and in an ammonia atmosphere.
Evaporation of ammonia from the
ceramic coating is done in a
separate section of the drying
chamber. The pattern trees then
are delivered to a second dip-coat-
ing unit.
Spill sand from the stuccoing
operation is returned by elevator
to the overhead chute for further
use. Sand is replenished by a pneu-
matic conveyor. The process just
described is repeated four times
in the system diagrammed in Fig.
5. Dipping and stuccoing units are
maintained by one operator.
Completed shell molds are loaded
onto fixtures hung from a mono-
rail chain conveyor that carries the
molds through a hot-water bath
for pattern removal. As the de-
waxed molds leave this operation,
a worker removes them from the
conveyor, inspects them, and sorts
them according to grade of steel
to be poured. One operator controls
the chain conveyor, drying cham-
bers, and dewaxing baths.
The entire moldmaking area is
air conditioned to maintain re-
quired temperature and humidity.
Automation of the shell-making
operation has eliminated manual
labor at the dip-coating and stuc-
coing areas in the atmosphere of
acetone and the silicate vapors
with suspended quartz powder.
Firing and Pouring—The shell
molds are mounted on conveyor
hangers, as shown in Fig. 6, with
each hanger accepting two small-
diameter molds or a single mold of
larger diameter. The pouring basin
is covered with a removable cap to
keep sand from entering the mold
and to fix the mold to the hanger.
57
-------
Fig. 6-Shell molds are placed on a hanger (1) before entering the gas-fired furnace
(2). As molds exit the furnace, they are lowered by a pneumatic hoist (3) into
a bed of sand heated by manifolds (41. They move with the rotary bed (5) to the
pouring station and then to the unloading station, where a pneumatic hoist
(6) lifts them out of the sand. Molds then pass through a cooling chamber (7). A
belt conveyor (8) catches spill refractory, and a trolley conveyor (9) moves
molds through the system.
The mold passes into the furnace
for firing at 900 C (about 1.650F).
The hanger follows a slit in the
roof of the furnace so that the con-
veyor chain, hanger carrier, and
track are outside the hot zone. Ex-
haust ventilation is provided along
the entire slit in the roof.
On leaving the oven, the fired
shells are immersed in a bed of
sand, fluidized by hot air, at the
rotary pouring machine. The chain
conveyor drives the trough in syn-
chronization through a sprocket.
Shells leave the fluidized zone
firmly embedded in the backup
sand. They enter a 6-m (20 ft)
pouring zone that takes up half
the circumference of the turntable.
Molds are poured from shank ladles
of 80-kg capacity (about 175 Ib).
Steel melts are prepared in 160-kg
(about 350-lb) induction furnaces.
The turntable continues its rota-
tion, and the poured molds cool to
about 1,200 C (about 2,200 F), after
which they are lifted out by an air
hoist. They then are moved by
chain conveyor to a water-spray
cooling chamber. On leaving the
cooling chamber, the poured molds
are removed from the conveyor
hangers, and the latter are returned
to the shell assembly station.
Shakeout, Cutoff—Poured shells
are placed manually on a shuttle
conveyor for movement to a vibra-
tor that shakes shell material from
the sprue of castings. The shuttle
carries the sprue of castings to a
cutoff unit that consists of an
annular cutting die mounted in a
press. Castings fall to a container
or a belt conveyor, and the riser is
ejected. The press stroke may be
pulsating to improve the cutoff
action.
That approach to cutoff was
made possible through adoption of
a feeding system of standard di-
mensions. Yield was sacrificed in
some instances for the sake of
automating the cutoff operation.
Final Cleaning — Complete re-
moval of ceramic from the castings
is achieved by an alkaline bath
and hot-water rinse in a two-
compartment, rotating barrel at the
rate of 450 kg (about 990 Ib) of
castings per hour. A vibrating feed-
er delivers the castings to the
barrel, and cycling through the
baths is automatic. Cleaned and
washed castings are delivered to
furnaces for normalizing treatment
under a protective atmosphere to
prevent scaling and decarburiza-
tion.
Following normalization, the
steel castings have a fine-grained,
homogeneous structure of pearlite
and ferrite. The decarburized zone
is .3 to .35 mm (.12 to .14 in.) deep.
Process Control—Control of the
entire system is from a central
office. Control consists of the
following functions:
• Remote automatic registration
of the number of pattern assem-
blies and shells made (usable,
rejected, fired) and of cutoff cast-
ing assemblies.
• Remote automatic registration
of shells in storage.
• Remote semiautomatic regis-
tration of the number of castings
by type sent to storage and de-
livered from storage as finished
products.
• Automatic recording of all
data on report form by automatic
electric typewriter.
• Remote automatic transmis-
sion of all report data to the plant's
computer center for preparing and
issuing to the shop detailed sched-
ules for starting up, production
output, and for processing reports
on fulfilment of the shop plan.
• Signaling the operating con-
dition of basic equipment.
• Automatic selective registra-
tion of operating and downtime of
basic equipment.
• Remote automatic monitoring
of availability of basic materials.
• Telephone control intercom
within shop.
• Radio communication within
shop for production purposes.
• Transmission of rapid chemi-
cal analyses of metal from labora-
tory to steel-melting department.
58
-------
ADDENDUM 2
ALLOY SUMMARIES
713LC/IN-738
INTERNATIONAL NICKEL
59
-------
preliminary data
ALLOY 713LC
LOW CARBON ALLOY 713C
The low carbon modification of alloy 713C* was developed by C. G. Bieber at the Bayonne Research
Laboratory of The International Nickel Company, Inc. to combine the good stress .rupture properties of
the base material with excellent room temperature ductility and strength. The combination of these
properties becomes highly desirable in such applications as the integrally cast wheel. The highly
stressed, heavy hub section of the wheel remains at a relatively low temperature while the thin leading
and trailing edges of the blades must withstand cyclic temperatures up to 1800 F, depending upon the
engine. Recent evidence has shown that alloy 713LC produced with a low iron content, i.e. less than
.50%, has superior mechanical properties to heats containing high iron, i.e. greater than 1.20%. Data
presented here will cover material manufactured to the recommended composition listed below as well
as alloy containing high iron as originally produced.
Composition — weight per cent
The nominal composition and recommended range to which the alloy is produced are shown in
the tabulation below:
Element Nominal Range
Carbon 0.05 0.03 - 0.07
Chromium 12.00 . 11.00 - 13.00
Molybdenum 4.50 3.80 - 5.20
Columbium + Tantalum 2.00 1.50 - 2.50
Aluminum 5.90 5.50 - 6.50
Titanium 0.60 0.40 - 1.00
Boron 0.01 0.005 - 0.015
Zirconium 0.10 0.05 - -.15
Silicon LAPt 0.50 max.
Manganese LAP 0.25 max.
Iron LAP 0.50 max.
Copper LAP 0.50 max.
Sulfur LAP 0.015 max.
Nickel Balance Balance
Effect of Corbon Content
Figure 1 illustrates the effect of carbon content on the room temperature tensile properties, while
Figure 2 shows its relationship to stress rupture properties. The data presented include results from
both laboratory and commercial melts. The apparent increase in stress rupture properties at "zero"
carbon over the values at 0.02% carbon does not reflect the true variation with carbon content, but
rather represents all laboratory heats produced with NiCb versus all the commercial melts produced
with FeCb.
* U.S. Patent »2,570,193, produced under license from The International Nickel Company, Inc.
t Low as possible
60
-------
CO
150
140
130
CO
Q.
O
O
O
~ 120
CO
CO
£ no
100
90
80
TENSILE STRENGTH
2 % YIELD STRENGTH
I
I
I
I
.02 .04 .06 .08 .10 .12 .14
CARBON CONTENT %
CD
Z
O
30
20
10
0 .02 .04 .06 .08 .10
CARBON CONTENT %
.12 .14
co
ce
o
o
LiJ
Figure 1. Room Temperature Tensile Properties vs. Carbon Content of As Cast, Vacuum Melted,
Vacuum Cast Alloy 713LC.
•— I700F/30.000 PSI
O---I800 F/22,000 PSI
.02 .04 .06 .08 .10 .12 .14
CARBON CONTENT %
15
0
• 1700 F/30,000 PSI
O- 1800F/22,000 PSI
I
0 .02 .04 .06 .08 .10 ' .12
CARBON CONTENT %
Figure 2. Stress Rupture Properties vs. Carbon Content ol As Cast, Vacuum Melted, Vacuum
Cast Alloy 713LC.
.14
61
-------
Physicol Properties - Low Fe Moteriol
Density
.289 Ibs/cu in (8.01 g/cu cm)
Melting Range (estimated)
2350-2410 F
Oxidation Resistance (See Figure 3)
Samples were given cyclic exposure by heating in air to 1900 F for 16 hours and cooling
for 8 hours.
Time, hrs.
16
32
48
64
80
96
112
Wt. Change, %
713LC IN-100
0.17
0.23
0.29
0.15
0.04
0.05
0.0
.02
.07
.14
.24
.24
.28
.38
Time, hrs.
128
144
160
176
192
208
Wt. Change, %
713LC IN-100
-0.14 -.44
- 0.07 - .48
-0.08
-0.08
- .62
- .82
58
UJ
z
-------
Mechanical Properties - Low Fe Material « .50%)
Tensile Properties - Cast to Size Bars (See Figure 4)
Test
Temp.
F
70
1200
1500
1700
0.2% Yield
Strength
psi
109,000
113,900
99,000
66,900
Tensile
Strength
psi
130,000
157,000
123,000
94,200
Elong.
Reduction
of Area
%
20.9
11.0
17.0
12.0
Tensile Properties — Machined from hub of wheel
Test
Temp.
F
70
70*
0.2% Yield
Strength
96,200
121,400
Tensile
Strength
101,000
140,500
Elong.
17.0
10.5
Reduction
of Area
20.0
17.5
•Solution Treated 2150 F - 2 hrs. - AC
Stress Rupture Properties - Cast to Size Bars (See Figure 5 and 6)
Life Elong.
hrs. %
Test
Temp.
F
1350
1400
1500
1500
1500
1700
1700
1800
1800
Stress
psi
90,000
85,000
60,000
40,000
40,000
30,000
20,000
22,000
15,000
201.0
81.7
131.5
3023.1
3500
66.6
1686.2
62.1
930.0
•Test stopped after 3500 hours. Bar had 3.6% creep.
on the bar indicated the following:
Test
Temp.
F
70
0.2% Yield
Strength
psi
88,500
Tensile
Strength
psi
110,800
4.0
3.1
10.7
10.7
(3.6)*
8.5
5.5
7.2
7.6
No. of
Tests
2
2
1
1
1
10
1
66
2
Room temperature tensile test
Elong.
10.0
Reduction
of Area
%
17.5
Effect of Iron Content on Stress Rupture Properties
Increasing iron decreases the high temperature strength of this alloy by lowering the solutioning tem-
perature of the gamma prime phase Nig (Al, Ti). It has been shown that the elevated temperature
stress rupture strength of alloy 713C and a similar alloy is adversely affected by the addition of iron
to master heats made with pure columbium. The following data indicate the effect of iron on several
laboratory melts of alloy 713LC produced with the columbium addition being made in the form of
ferrocolumbium in one case and nickel columbium in the other.
63
-------
Test Conditions: 1800 F - 22,000 psi
NiCb
(approx. .15% Fe)
FeCb
(approx. 1.50% Fe)
No. of Melts 12 7
Average Life, hrs. 65.7 42.8
Range of Life, hrs. 37.3 - 101.9 29.4 - 64.2
Average Elong. % 8.2 6.8
Range of Elong. % 4.2 - 10.6 3.5 - 10.6
160
L75 140
a.
O
o
0
co~ 120
CO
UJ
tr
i-
co
I(J(J
80
cr\
— *•«
^^MM
TENSILE STRENGTH ^y
^^"•B
M^^M
—^
0.2% YIELD I ST
• -
•— •»
ELONG. -"*
,
""• •*•
^^MM
/
/
RENG1
s
f
H^x
~N
^-~
\
^
RED AREA
-..,
-
i^ita
- —
k' —
*~^
\
s
\
*x
\
\
\
\
>
•"^
\
\
y
\
C\
^
~2f\ 3®
z
o
f.\J (—
1
10 |
0 u
0 200 400 600 800 1000 1200 1400 1600 1800
TEMPERATURE,F
Figure 4. Typical Tens/'/e Properties o/ /Is Cast, Vacuum Melted, Vacuum Cast Alloy 713LC.
(Low Fe Material)
CO
o.
o
o
o
CO
CO
UI
o:
t—
CO
500 1000
5POO 10,000
TIME.HOURS
Figure 5. Stress Rupture Data On As Casr, Vacuum Melted, Vacuum Casr Alloy 713LC.
(Low Fe Material)
64
-------
Mechanical Properties - High Fe Material (Approx. 1.50%)
Tensile Properties - Cast to Size Bars (See Figure 7)
Test
Temp.
F
70
1000
1200
1350
1500
1700
0.2% Yield
Strength
psi
109,400
108,400
109,900
111,100
87,200
55,700
Tensile
Strength
psi
133,100
132,200
138,100
145,300
124,500
88,400
Tensile Properties — Machined from hub of wheel
Test
Temp.
F
70
70*
1350
0.2% Yield
Strength
psi
89,200
101,600
92,600
Tensile
Strength
psi
94,300
112,800
108,100
Elong.
%
13.2
8.0
6.0
8.0
12.0
9.0
Elong.
_%
16.0
18.2
11
•Solution Treated 2150 F - 2 hrs. - AC
Stress Rupture Properties - Cost to Size Bars (See Figure 6)
Test
Temp.
F
1350
1500
1700
1800
Stress
psi
90,000
60,000
30,000
22,000
Life
hrs.
64.6
68.0
57.8
42.8
Elong.
%
4.0
5.3
4.0
6.8
Reduction
of Area
%
20.5
19.5
14.5
21.0
17.0
13.5
Reduction
of Area
11.0
14.3
5.5
13.3
TEMPERATURE, F
IUU
eo
60
40
£
20
£
S 10
B
6
4
^
AUO
>
f 7IJ
^x.
s
LCIH
^N
X
Ft)
xV
--«*
i — /
\N
LLOK
A
71 J
\
CILO
KFll
34 38 4Z 46
SO
tlxlO
"3
Figure 6. Larson Miller Stress Rupture Parameter Curve For Alloy 713LC.
65
-------
0 200 400 600 800 1000 1200 1400 1600 1800
TEMPERATURE,F
Figure 7. Typical Tensile Properties ol As Cast Vacuum Melted Vacuum Cast Alloy 713LC.
*(High Fe Material)
Dynamic Modulus of Elasticity (See Figure 8)
Test
Temp.
F
70
200
400
600
800
Dynamic
Modulus
28.55 x
28.10
27.31
26.59
25.84
106
Test
Temp.
F
1000
1200
1400
1600
1800
Dynamic
Modulus
24.97 x 10
24.00
23.09
21.61
19.72
Fatigue Data
Reversed stress axial fatigue tests on machined bars in the as cast condition indicated the
Q
following endurance limits at 10 cycles:
Test
Temp.
F
1200
1500
Grain
Size
12,500
11,500
Endurance Limit, psi
(108 Cycles, A =00 , Kt = 1.0)
26,000
25,000
As with the standard alloy 713C, the low carbon version exhibited a cleavage type of fracture
at 1200 F.
Effect of Casting Temperature
Castings of alloy 713LC are normally poured at temperatures of approximately 3000 F to ensure
soundness, fill and optimum mechanical properties. The lower carbon content of this material
requires closer control of casting temperatures due to its marked influence on properties as
indicated by the following data:
66
-------
Effect of Casting Temperature - High Fe Material (Approx. 1.50%)
Room Temperature Tensile Data
Casting
Temp.
F
0.2% Yield
Strength
psi
Tensile
Strength
psi
Elong.
Reduction
of Area
Condition: 1900 F Mold, Non-inoculated
P* 4 200
P 4 590
104,200
110,500
126,800
121,600
8.5
15.3
11.2
18.2
Condition: 1650 F Mold, Non-inoculated
P 4 200
P 4 500
107,200
105,700
133,800
127,500
12.8
17.2
18.1
23.2
Condition: 1600 F Mold, Non-inoculated
P
P
4 250
4550
117,000
108,300
138,000
130,800
9.0
16.0
12.0
24.0
Condition: 1400 F Mold, Non-inoculated
P 4 350
P 4550
*P = Plateau = Liquidus
Stress Rupture Data
114,500
108,300
130,000
130,800
7.0
16.0
8.8
24.0
Casting
Temp. F
P
P
P
4250
4350
4550
1700 F/30,000 psi
Hrs. Elong.
id
S
N
s
<
\
•
/
\
^x
50..
56.
35.
»
\
^
/
3
8
B
k.
S,
V
\
\
2.
4
6.
[\
'^ J
y
,
7
0
7
\
\\
\
0 200 400 (00 800 1000 1200 1400 1600 1600
TEMPERATURE,f
1800 F/22,000 psi
Hrs. Elong.
17.2
32.3
42.8
2.7
4.0
6.8
Figure 8. Dynamic Modulus of Elasticity of As Cast, Vacuum Melted, Vacuum Cast Alloy
713C & Alloy 713LC. (High Fe)
67
-------
IN-738
Preliminary Data
INTRODUCTION
IN-738* is a vacuum cast, precipitation hardened, nickel-base alloy possessing ex-
cellent high temperature creep-rupture strength combined with hot corrosion resist-
ance superior to that of many present day high strength superalloys of lower chrom-
ium content. It is designed to provide the turbine industry with an alloy which will
have good creep strength up to 1700-1800F combined with ability to withstand long
time exposure to the hot corrosive environments associated with the engine.
IN-738 exhibits tensile properties superior to and elevated temperature stress-rupture
properties comparable to those of the widely used alloy 713C, along with substantial-
ly better sulfidation resistance.
Three 2500 Ib. semi-commercial heats of IN-738 have been melted to date. Data
reported herein were obtained with material from those heats.
COMPOSITION - Weight Per Cent
Element
Carbon
Cobalt
Chromium
Molybdenum
Tungsten
Tantalum
Columbium
Aluminum
Titanium
Aluminum + Titanium
Boron
Zirconium
Iron
Manganese
Silicon
Sulfur
Nickel
Nominal
0.17
8.50
16.00
1.75
2.60
1.75
.90
3.40
3.40
6.80
.01
.10
LAP**
LAP
LAP
LAP
Balance (60)
Range
0.15
8.00
15.70
1.50
2.40
1.50
.60
3.20
3.20
6.50
.005
.05
.50 max.
.20 max.
.30 max.
.015 max.
Balance
0.20
9.00
16.30
2.00
2.80
2.00
1.10
3.70
3.70
7.20
.015
.15
Low as possible
HEAT TREATMENT
This alloy achieves the best combination of mechanical properties after the following
heat treatment: 2050F/2 hr/AC + 1550F/24 hr/AC. All properties in this bulletin
were obtained with material given this treatment.
Patent pending.
68
-------
MINIMUM MECHANICAL PROPERTIES
No property specification has yet been written for IN-738; however, based on material
produced to date, the alloy appears capable of at least meeting the stress rupture
property levels usually specified for alloy 713C. The tensile properties appear to
offer a significant advantage over alloy 713C.
PHYSICAL PROPERTIES
DENSITY
- 0.293 lb/in.3 (8.11 g/cm3)
MELTING RANGE - 2250 - 2400F (1232-1315C)
STABILITY - While long time elevated temperature stability can be demonstrated
only by long time exposure, a mathematical analysis based on electron vacancy
concentration (see Appendix I) is useful in indicating the susceptibility of an alloy
to form sigma. The electron vacancy number, Nv, of IN-738 is 2.28. To ensure stabil-
ity in this alloy, it is recommended that the Nv should not exceed 2.36. In the
material produced to date, no deleterious intermetallic phase precipitation has been
observed in heat treated material even after 4,000 hr. exposure at 1500F under a
stress of 40,000 psi.
THERMAL EXPANSION (See Figure 1)
Temperature
(F)
70
200
400
600
800
1000
1200
1400
1600
1800
Thermal Expansion Data for
IN- 738, Heat Treated
2050F/2 hrs/AC + 1550F/2 hrs/AC
Mean Coefficient
of Expansion
from 70 F to
Indicated Temp.
6.45 x 10-6/°F
6.75
7.15
7.55
7.75
8.05
8.25
8.55
8.85
Instantaneous
Coefficient
of Expansion
at Temperature
6.2 x 10-6/°F
6.7
7.4
8.0
8.65
9.01
9.1
10.15
10.75
11.6
69
-------
11.0
X I0'°
UJ
K S- 9-0
UJ ,)S
8.0
7.0
6.0
U. X
O
UJ
O
LU
O
INSTANTANEOUS
COEFFICIENT (e&
TEMPERATURE-
*MEAN LINEAR
COEFFICIENT
(from 70 F to
indicated temperature)
400 800 1200
TEMPERATURE, F
Figure 1. Thermal Expansivity of IN-738.
1600
2000
CHEMICAL PROPERTIES
A. OXIDATION
1. Static Test - 1000 hi., still air
Weight Change
Alloy
713C
IN - 738
Udimet 500 (cast)
Udimet 700
1800F
+ 0.6 mg/cm2
-16
-22
- 8
2000F
+ 29 mg/cm2
-102
-328
2. Cyclic Test — Samples were given a cyclic exposure by heating in air at 1800F
for 22 hr. and then cooling to RT for 2 hr.
Alloy
713C
IN-738
Wt. Loss in 1000 Hr.
0.7 mg/cm2
14 mg/cm
B. SULFIDATION
IN-738 has been evaluated in crucible, rig and engine tests in comparison with a
number of other alloys. The crucible tests generally consisted of immersion of
1/4" x 1/4" x 1" rectangular samples in a molten mixture of salts followed by
descaling operations to determine sample weight loss. The rig tests were per-
. formed generally by rotating samples of pin-shapes or airfoil shapes in a com-
bustion stream of fuel containing sulfur. Intermittent cooling cycles were employed
to simulate engine operation. During the heating portion of the cycle, salts and/or
alkaline metal particles were injected into the stream as detailed in the following
tabulation.
70
-------
The test results obtained are shown below:
1. Crucible Test, 10% NaCl/90% Na2S04 - 1700F
Alloy
Alloy 713C
Udimet 500 (cast)
IN - 738
Time, Hr.
2-4
40-100
250 - 300
Remarks
Destroyed
Gross Attack
Slight Attack
2. Crucible Test (controlled replacement of salt) -1650F -300 Hr.
Alloy
Udimet 500 (cast)
.IN -738
10% NaCI/90% Na2S04
Wt. Loss, mg/cm
6
7
25%NaCI/75%Na2S04
Wt. Loss, mg/cm
16
14
3. 1000 Hr. Cyclic Rig Test - 1600F - Diesel Fuel (1% Sulfur) Air/Fuel Ratio:
30/1, 5 ppm sea salt
Alloy
IN -738
Alloy 713C
Udimet 500 (wrought)
Surface Loss, mg
3.3
38 - 130+ **
1.7- 3.8
Max. Penetration, mil.
19
60 - 130+ **
12- 13
4. 1000 Hr. Cyclic Rig Test - 1800F - Diesel Fuel (1% Sulfur) Air/Fuel Ratio:
30/1, 5 ppm sea salt
Alloy
IN -738
Alloy 713C
Udimet 500 (wrought)
Udimet 500 (cast)
Surface Loss, mg
3.1
130+ **
3.5
8.8
Max. Penetration, mil.
15
130+ **
21
36
* * Specimen consumed
5. Sulfidation Cyclic Rig Test (150 Hr.) - JP-5R Fuel, 3.5 ppm salt, about 17/1
Air/Fuel Ratio
Alloy
IN -738
Alloy 713C
Udimet 700
Peak Temperature
1550F
Wt. Loss, gms.
2.1
5.5
4.0
1750F
Wt. Loss, gms.
4.0
7.1
7.9
6. Sulfidation Cyclic Rig Test (173 Hr.) - JP-5R Fuel, 3.5 ppm salt, about 17/1
Air/Fuel Ratio
Cycle of 1550F/3 min. - 1850F/2 min. - cooled 2 min.
Alloy
B1900
IN -738
MDL20
Mar M421
Wt. Loss, gms.
6.8
2.5
3.0
4.2
71
-------
'10 100 1000 10.000
TIME. HR
Figure 2. Time VS. Weight Loss Plots For Several Alloys at 1450 F in Presence
of Eutectic Na2S04-MgS04 and 0.15% S02.
7. Combustion Chamber Test-Fuel Oil doped with 5 ppm Na, .SppmMg, 1%S-1450F
Alloy
IN -738
X-45
Udimet 500 (wrought)
Wt. Loss, % in 50 Hr.
.183
.206
.143
8. Crucible Test Na2S
Alloy
IN- 738
Udimet 500 (cast)
Alloy 713C
04, MgS04 under a gas of .15% S02, 2.25 Co, N2 - 1450F
Wt. Loss (mg/cm2) after
32 Hr.
.32
.35
8.3
64 Hr.
.56
.51
23.
136 Hr.
.97
.71
90.
250 Hr.
1.4
500 Hr.
3.3
9. GasTest-1800F(100Hr.)-FlowingH2Sand S02-rich gas to accelerate corrosion
Alloy
IN- 738
Alloy 713C
Udimet 700
Wt. Loss, mg/cm
310
770
1440
10. Engine Test - 1780F (45 Hr.) (.75 ppm sea salt) 40 min. cycle (30 min. at
1780F, 10 min. ram cool air)
Alloy
Alloy 713C
Mar M246
TRW VIA
235D
IN - 738
Udimet 710
Rating (higher number
indicates increasing resistance)
1
1.1 times corrosion resistance of 713C
1.4
1.9
. 6.2
5.8
The behavior of IN-738 and several other alloys in a eutectic mixture of Na2S04
- MgS04 at 1450F is shown in Figure 2.
72
-------
MECHANICAL PROPERTIES
TENSILE PROPERTIES
Typical properties obtained on heat treated, cast-to-size test bars (fine grain 5 1/8"
diameter) are as shown below. Property ranges are plotted in Figure 3 in comparison
to those of 713C.
Temp.
F
RT
1350
1500
1600
1700
1800
0.02%
Yield Strength
psi
128
_
— •
—
_
-
0.2%
Yield Strength
ksi
138
122
100
80
59
50
Tensile
Strength
ksi
159
145
127
112
81
66
Elong.
%
5.5
3
3
11
13
10
R.A.
%
5
4
3
13
14
15
Limited data obtained at R.T. on coarse grain (3/32-5/16" diameter) bars have been
essentially the same as shown above.
Stress Rupture Properties (See Figure 4)
Rupture properties obtained on heat treated, fine-
grain, cast-to-size test bars are as follows:
Temp.
F
1350
1350
1350
1400
1400
1450
1500
1500
1500
1600
1700
1700
1700
1800
1800
1800
1800
1800
1825
Number
of Tests
1
11
1
1
2
1
1
1
4
2
1
6
1
1
1
19
1
1
1
Stress
psi
100,000
90,000
80.000
90,000
85,000
60,000
70,000
55,000
40,000
40,000
35,000
33,000
26,000
25,000
24,000
22,000
18,000
15,000
16,000
Life :
Hr.
93
139-291
Avg. 211
452
89
130-155
976
29
261
2794-3947
Avg. 3205
312-430
29
97-109
Avg. 104
190
55
65
39-96
Avg. 78
116
269
148
Elong.
.%
13
4-7
6
4
4
6
4
14
11
4-6
5
9
15
6-11
8
14
6
—
12-20
15
24
-
6
R.A.
%
20
8-9
9
6
8
-
5
17
14
4-8
6
13
17
13
13
—
-
—
19-25
23
27
-
14
<=> "RT 1000 1200 1400 1600 1800 2000
TEMPERATURE, F
Figure 3. Typical Tensile Properties of IN-738
Compared to those of 713C.
73
-------
Limited rupture data on coarse grain (1/4") cast-to-size bars are as follows:
Temp.
F
1350
1350
1500
1500
1700
1700
1800
1800
1800
1800
Number
of Tests
2
1
1
1
1
2
3
4
1
1
Stress
psi
90,000
88,000
70,000
55,000
35,000
33,000
29,000
22,000
20,000
18,000
Life
Hr.
216
224
29
269
41
52-116
9- 16
Avg. 14
30-95
Avg. 66
128
132
Elong.
%
4.5-6
9
10
8
11
6-10
15
15
6-16
12
10
13
R.A.
%
8-11
12
12
10
16
12-17
18-32 '
27
17-30
23
27
25
A Larsen -Miller parameter plot of the above data is
shown in Figure 5. Data on 713C and IN-100 are
shown for comparison.
100 rr
• FINE GRAIN (£ 1/8")
x COARSE GRAIN (S 1/4")
100 1000
RUPTURE LIFE, HRS
Figure 4. Stress Rupture Properties of Cast-
fo-Size Bars of IN-738.
10,000
5
L
>
9
»
1
J
C
l>
1
^^
-
-
-
-
~ • •^•B
55$.
^^
"^
- IN-IOO
— IN-738
— ALLOY 7I3C
1 1
5v£x
X
^
1
_
-
^
-
-
-
40 42 44 46
P - T (20* Log
48
50
n
Figure 5. Larsen-Miller Stress Rupture Parame-
ter Plot Comparing IN-738, 1N-100 and 713C.
74
-------
IMPACT PROPERTIES
Unnotched Charpy impact value (ft.-Ib.) of samples tested at R.T. after various elevated
temperature exposures are as follows:
Grain Size
Fine < (1/8")
Coarse > (1/4")
Impact
Value
Prior to
Exposure
56
37
Room Temperature
Impact
1200F
500
hr.
44
54
1000
hr.
30
38
Value After Expc
1500F
500
hr.
20
20
1000
hr.
13
16
sure at
1700F
500
hr.
14
17
1000
hr.
10
14
THERMAL FATIGUE RESISTANCE
The thermal fatigue resistance of IN-738 and of several other cast alloys was de-
termined using a fluidized bed for heat transfer. This method involved alternate 2
minute immersion of 1-5/8" diameter tapered disc specimens, with 0.010 in. edge
radius, in hot and cold beds.
Thermal Fatigue Cycles to First Crack
Alloy
713C
• IN-100
IN -738
Peak Temperature of
1472F (800C)
>1462
>1372
1790
1652F (900C)
107
107
150
1832F (1000C)
27
29
13
APPENDIX I
METHOD FOR CALCULATION OF ELECTRON VACANCY NUMBER
1. Convert the composition from weight per cent to atomic per cent.
2. After long time exposure in the Sigma forming temperature range, the MC carbides
tend to transform to M23(^(5.
a. Assume one-half of the carbon forms MC in the following preferential order
TaC, CbC, TiC.
b. Assume the remaining carbon forms M23C<5 with the M comprising 23 atoms
of Cr.
3. Assume the boron is tied up as Mo 38 3.
4. Assume the gamma prime to be (Ni-8Co.2)3 (Al, Ti, Ta, Cb)
5. Assume the residual matrix will consist of the atomic per cent minus those atoms
tied up in the carbide reaction, boride reaction, and the gamma prime reaction.
The total of these remaining atomic percentages gives the atomic concentration in
the matrix. Conversion of this on a 100% basis gives the atomic per cent of each
element remaining in the matrix. It is this percentage that is used in order to
calculate the electron vacancy number.
6. The formula for calculation of the electron vacancy number is as follows:
Nv = .66 Ni + 1.71 Co + 2.66 Fe + 4.66 Cr + 6.66 Zr + 9.66 (Mo + W)
75
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