Designation: A 982 – 02

Standard Specification for

Steel Forgings, Stainless, for Compressor and Turbine
Airfoils1
This standard is issued under the fixed designation A 982; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope* 5. Manufacture
1.1 This specification covers stainless steel forgings for 5.1 Melting Process—All melting processes of Specifica-
compressor and turbine bucket, blade, and airfoil applications. tion A 788 are permitted unless Supplementary Requirement
1.2 The values stated in inch-pound units are to be consid- S1 is invoked by the purchaser.
ered the standard. 5.2 Forging Process—Either the closed impression die or
the open die forging processes may be utilized unless the
2. Referenced Documents purchaser specifies one or the other.
2.1 ASTM Standards: 5.2.1 Forging Temperature—The maximum part tempera-
A 275 Test Method for Magnetic Particle Examination of ture during forging shall be 2150°F.
Steel Forgings2 5.3 Heat Treatment—Heat treating all forgings is required
A 788 Specification for Steel Forgings, General Require- in accordance with Table 1 to develop the required mechanical
ments2 properties.
E 381 Method of Macroetch Testing Steel Bars, Billets, 5.3.1 Number of Heat Treatments—Two complete heat
Blooms, and Forgings3 treatments, consisting of an austenitize, quench and temper, are
E 562 Practice for Determining Volume Fraction by Sys- permitted. Purchaser approval is required prior to any addi-
tematic Manual Point Count3 tional heat treatments.
5.3.2 Temperature Variation—Heat treating temperatures
3. Ordering Information shall be controlled in the range of 625°F.
3.1 In addition to the ordering information required by 5.4 Stress Relief—When heat treatment for mechanical
Specification A 788, the purchaser shall include a sketch or properties is followed by straightening, a stress relieving heat
written description of the forging with the inquiry and order. treatment is required at a temperature meeting the requirements
of Table 1.
4. General Requirements 5.4.1 Quenching after Stress Relief—Water or oil quenching
4.1 Materials supplied to this specification shall conform to of stress relieved forgings is prohibited.
the requirements of Specification A 788 which outlines addi-
tional ordering information, manufacturing requirements, test- 6. Chemical Composition
ing and retesting methods and procedures, marking, certifica- 6.1 The steel shall conform to the requirements for chemical
tion, product analysis variations and additional supplementary composition prescribed in Table 2.
requirements.
4.2 If the requirements of this specification are in conflict 7. Mechanical Properties
with the requirements of Specification A 788, the requirements 7.1 Tension, Impact and Hardness Tests—All testing shall
of this specification shall prevail. be performed after heat treatment and stress relief, as appli-
cable. The test specimens shall meet the requirements of Table
1
3.
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
7.1.1 Number of Tests—A minimum of two forgings from
A01.06 on Steel Forgings and Billets. each lot shall be randomly selected for longitudinal tensile,
Current edition approved Sept. 10, 2002. Published June 2003. Originally impact, and hardness testing. Hardness values of the tension
published in 1998. Last previous edition approved in 2001 as A 982–001. test specimen shall be reported with the tensile data.
2
Annual Book of ASTM Standards, Vol 01.05.
3
Annual Book of ASTM Standards, Vol 03.01.

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

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 A 982 – 02
TABLE 1 Heat Treatment, °F
Grade A Grade B Grade C Grade D Grade E Grade F
Classes 1 & 2 Class 1 Class 1 Class 2 Classes 1 & 2 Class 1 Class 2 Class 1
Austenitizing 1725-1775 1600-1750 1825-1875 1725-1875 1875-1925 2075-2125 1725-1775 1875-1925
Quenching Air or liquid Air or liquid Air or liquid Air or liquid Air or liquid Air or liquid Air or liquid Air or liquid
Single tempering 1050 min 1050 min 1050 min 1050 min 1150 min 1250 min 1100 min ...
Double tempering ... ... 1025 min 1025 min ... ... ... ...
Aging ... ... ... ... ... ... ... 1135-1165
Stress Relieving 1025 min 1025 min 1000 min 1000 min 1100 min 1200 min 1050 min 1100 min

TABLE 2 Chemical Requirements

Composition %
Grade A Grade B Grade C Grade D Grade E Grade F
UNS Designation S41000 S41005 S41428 S42225 S41041 S17400
Carbon 0.15 max 0.10-0.15 0.10-0.17 0.20-0.25 0.13-0.18 0.07 max
Manganese 1.0 max 0.25-0.80 0.65-1.05 0.5-1.0 0.4-0.6 1.0 max
Phosphorus, max 0.018 0.018 0.020 0.020 0.030 0.040
Sulfur, max 0.015 0.015 0.015 0.010 0.030 0.030
Silicon 0.5 max 0.5 max 0.10-0.35 0.20-0.50 0.5 max 1.0 max
Nickel 0.75 max 0.75 max 2.25-3.25 0.5-1.0 0.5 max 3.0-5.0
Chromium 11.5-13.0 11.5-13.0 11.25-12.75 11.0-12.5 11.5-13.0 15.0-17.5
Molybdenum 0.5 max 0.5 max 1.5-2.0 0.9-1.25 0.20 max ...
Vanadium ... Report only 0.25-0.40 0.20-0.30 ... ...
Tungsten ... 0.10 max 0.10 max 0.9-1.25 ... ...
Nitrogen ... 0.08 max 0.020-0.045 Report only ... ...
Aluminum ... 0.025 max 0.025 max 0.025 max 0.05 max ...
Columbium ... 0.20 max ... 0.05 max 0.15-0.45 0.15-0.45
Cobalt ... ... ... 0.20 max ... ...
Titanium ... 0.05 max 0.05 max 0.025 max ... ...
Copper ... 0.15 max 0.15 max 0.15 max ... 3.0-5.0
Tin ... 0.05 max 0.05 max 0.02 max ... ...

TABLE 3 Tensile, Impact, and Hardness Requirements

Grade A Grade B Grade C Grade D Grade E Grade F
Class 1 Class 2 Class 1 Class 1 Class 2 Class 1 Class 2 Class 1 Class 2 Class 1
Tensile strength, min, ksi 100 110 110 145 160 140 140 115 110 135
Yield strength, min, ksi, 0.2 % offset 70 80 90 115 120 90 100 75 80 105
Elongation in 2 in., min, % 20 18 18 15 16 13 13 15 18 16
Reduction of area, min, % 60 50 50 30 50 30 35 50 55 50
Impact strength, min, av., Cv, Rt, ft-lb 30 25 30 30 40 8 13 20 25 41
Hardness, Brinell, max 255 269 269 352 375 331 331 277 262 341

7.1.1.1 Lot Size—A lot shall consist of all forgings of the 8.2 Nondestructive Tests—Nondestructive testing and cor-
same size from one electric furnace heat of steel and heat responding acceptance criteria shall be as specified by the
treated either in the same charge in either a batch furnace or a purchaser.
continuous type furnace.
7.1.1.2 Continuous Heat Treating Furnaces—Test forgings 9. Certification and Reports
shall be taken from each of the first and last push or tray to exit 9.1 All tests required by this specification shall be made by
the furnace. Additional forgings shall be taken so that the the manufacturer and reported on a certificate of test to the
maximum time between samples is 4 h. purchaser. Each test certificate shall include the following
7.1.1.3 Test Locations—One tension test specimen and one items:
set of three impact test specimens shall be machined from the 9.1.1 Purchase order number.
center portion of the air foil vane section. 9.1.2 Forging identification number.
7.1.2 Forging Hardness Testing: 9.1.3 Specification number and yeardate of issue, grade, and
7.1.2.1 Batch Type Furnaces—A minimum of 10 % of the class.
forgings in each lot shall be hardness tested. 9.1.4 Heat number.
7.1.2.2 Continuous Type Furnaces—Samples for hardness 9.1.5 Lot number and size.
testing shall be taken from every other tray or push. 9.1.6 Mechanical properties including tension, impact, and
hardness.
8. Nondestructive Examination 9.1.7 Hardness data tabulation for each forging tested.
8.1 General Requirements—All forgings shall be free of 9.1.8 Heat treating and stress relieving temperature and
cracks, seams, laps, shrinkage, and similar discontinuities. times.

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 A 982 – 02
9.1.9 Results of any specified supplementary requirements. forging. Material shall be segregated according to drawing,
9.1.10 Statement that the forgings were manufactured, heat, and lot numbers.
sampled, tested, and inspected in accordance with this speci-
fication and that the results satisfied the requirements. 11. Keywords
10. Marking 11.1 compressor airfoils; stainless steel forgings; turbine
10.1 The part number and a unique lot control designator, or airfoils
heat number, shall be stenciled or legibly painted on each

SUPPLEMENTARY REQUIREMENTS

The following supplementary requirements shall apply only when specified by the purchaser in the
inquiry, contract, and order. Details of these supplementary requirements shall be agreed upon by the
manufacturer and purchaser.

S1. Secondary Melting and Refining S7. Microstructure

S1.1 ESR or VAR is required. Use of either is permitted S7.1 The microstructure shall be uniformly fine grain tem-
unless otherwise specified. pered martensite with no more than 1 % delta ferrite.
S2. Ingot Chemical Analysis S7.2 Metallographic inspection shall be performed at 100x
magnification to determine the metallurgical structure, grain
S2.1 If consumable electrode remelting is used, then chemi- size, decarburization, and delta ferrite content. Visual estima-
cal analyses of each remelted ingot shall meet the chemical tion for the volume fraction of delta ferrite of various repre-
composition requirements listed and shall be reported. sentative areas of examination is acceptable. When the visual
S3. Macrostructure estimation method indicates the delta ferrite content is greater
than the allowed limit, the manufacturer may employ Practice
S3.1 Samples shall be taken from the top and bottom of the
E 562 for determining the acceptability of a lot.
first and last ingot of each heat. The structure of the starting
billets shall meet the criteria of Method E 381, S-3, R-2, C-3 # S7.3 A specimen shall be removed from the airfoil section
36 in.2 and S-3, R-3, C-3 > 36 in.2 on one test forging per heat treat lot. The plane of polish of the
specimen shall be parallel to the axial centerline of the forging.
S4. Root Attachment Zone Mechanical Properties The area examined shall include both the concave and convex
S4.1 Testing for mechanical properties of the root attach- vane surfaces.
ment area is required. The type, number, location, and orien- S7.4 Surface decarburization of forgings shall not exceed
tation of the tests shall be specified by the purchaser. 0.06 in.
S5. Magnetic Particle Inspection S8 Hardness Testing
S5.1 Each forging shall be magnetic particle inspected in S8.1 One hardness test is required on the surface of the
accordance with Test Method A 275. The maximum accept- turbine rotor attachment portion on each forging. When speci-
able indication size shall be 1⁄8 in. unless otherwise specified by fied by the purchaser, forgings shall be hardness tested for
the purchaser. surface hardness on the air foil vane section.
S6. Ultrasonic Inspection
S6.1 Ultrasonic inspection is required. The test method, S9. Minimum Hardness Requirements
location, and acceptance criteria shall be as agreed upon by the S9.1 When agreed upon by the purchaser and producer, a
purchaser and producer. minimum hardness value is required.

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 A 982 – 02
SUMMARY OF CHANGES

Committee A01 has identified the location of the following changes to this standard since A 982/A 982M-01
that may impact the use of this standard.

(1) Added UNS Numbers to Table 2.

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