ASTM B637 Specification

Scope

This specification covers hot- and cold-worked precipitation-hardenable nickel alloy rod,  bar, forgings, and forging stock for moderate or high temperature service (Table 1).
The values stated in inch-pound units are to be regarded as standard, The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

Chemical Requirements

The material shall conform to the requirements as to chemical composition prescribed in Table
1.If a product (check) analysis is performed by the purchaser, the material shall conform to the product (check) analysis variations prescribed in Specification B880.

ElementComposition Limits, %
UNS
N07750 (Formerly Grade 688)
UNS
N07718 (Formerly Grade 718)
UNS N07080
(Formerly Grade 80A)
UNS
N09925
Carbon0.08 max0.08 max0.10 max0.03 max
Manganese1.00 max0.35 max1.00 max1.0 max
Silicon0.50 max0.35 max1.00 max0.5 max
Phosphorus0.015 max0.03 max
Sulfur0.01 max0.015 max0.015 max0.03 max
Chromium14.00-17.0017.0-21.018.00-21.00
Cobalt1.00 maxA1.0 maxA
Molybdenum2.80-3.302.5-3.5
Columbium (Nb) + tantalum0.70-1.204.75-5.500.5 max (Nb only)
Titanium2.25-2.750.65-1.151.80-2.701.9-2.40
Aluminum0.40-1.000.20-0.800.50-1.800.1-0.5
Zirconium
Boron5.00-9.000.006 max
IronremainderB3.00 max22.0 min
Copper0.50 max0.30 max1.5–3.0
Nickel70.00 min50.0-55.0remainderB42.0–46.0

Note :

A. If determined.
B. The element shall be determined arithmetically by difference.

Mechanical Requirements

1) Unless otherwise specified, the material shall be supplied in the cold worked or solution treated condition, suitable for subsequent age hardening.
2) The cold worked or solution
treated material shall be capable of meeting the mechanical property requirements of Table 3, and the stress rupture lequirements of Table 4 (except alloys UNS N07022 , N09925 and N07725), following the precipitation hardening treatment described in Table 2.
3) When the material is to be supplied in the cold worked or solution treated plus aged condition, the requirements of Table 3 and Table 4 (except alloys UNS N07022, N09925 and N07725) shall apply, with the precipitation hardening
treatment of Table 2, or as agreed upon between the purchaser and the manufacturer as part of the purchase contract,

Heat Treatment

AlloyRecommended
Annealing Treatment
Recommended Solution
Treatment
Recommended Stabilizing
Treatment
Precipitation Hardening
Treatment
UNS
N07750 Type 1 (Service above 11OO°F) (593°C)
2100 ± 25 °F (1149 ± 14°C), hold 2 to 4 h, air cool1550 ± (843 ± 14 °C),
hold 24 h, air cool
1300 ± 250 °F (704 ± 14°C), hold 20 h, air cool or furnace
cool
UNS N07750 Type 2 (Service up to
1100°F) (593°C)
1800 ± 25°F (982 ± 14°C), hold 1/2 h min, cool at rate equivalent to air cool or
faster.
1350 ± 25°F (732 ± 14°C),
hold 8 h, furnace cool to 1150 ± 25°F (62 1 ± 14°C), hold until total
precipitation
heat
treatment has reached 18 h, air cool
UNS
N07750 Type 3
1975 – 2050°F (1079-1121°C), hold 1 to 2 h, air cool.1300 ± 25°F (704 ± 14°C), hold 20 h, + 4 — O h, air cool.
UNS
N07718
1700 to 1850°F (924 to 1010°C), hold 1/2 h min, cool at rate equivalent to air
cool
or faster.
1325 ± 25 °F (718 ± 14°C), hold at temperature for 8 h, furnace cool to 1150 ±
25 °F (621 ± 14°C), hold until precipitation heat treatment time has reached 18
h, air cool.
UNS
N07080
1950 ± 25°F (1066 ±
14± 25°C), hold 8 h, air cool
1560 ± 25°F (849 ± 14°C), hold 24 h, air cool.1290 ± 25°F (699 ± 14°C), hold 16 h, air cool.
UNS
N09925
1825 to 1875°F (996 to
1024°C), hold % min, and 4 h max, cool at rate equivalent to air cool or faster
1365 ± 250°F (740 ±
14°C), hold at temperature for 6 to 9 hr, furnace cool to 1150 ± 25°F (621 ±
hold
until total precipitation heat treatment time has reached 18 h, air cool or
faster

Tensile and Hardness Requirements

AlloyHeat TreatmentTensile Strength, min, psi [MPa]Yield Strength (0.2 % offset), min, psi [MPa]Elongation in 2 in. [50 mm] or 4D, min, %Reduction of Area, min, %Brinell Hardness
UNS
N07750 Type 1
solution at 2100°F [1149°C] + stabilize + precipitation harden140 000 [965]90 000 [620]8262 min
UNS
N07750 Type 2C
solution at 1800°F [982°C] + precipitation harden170 000 [1170]115 000 [790]1818302 to 363
UNS
N07750 Type 2D
solution at 1800°F [982°C] + precipitation harden170 000 [1170]115 000 [790]15 [10]E15 [12]E302 to 363
UNS
N07750 Type 3
solution anneal at 2000°F [1093°C] + precipitation harden160 000 [1103], min 185 000 [1276], max100 000 [689], min 130 000 [896], max2020267-363, Bm 27-40, Rc
UNS
N07718
solution + precipitation harden185 000 [1275]150 000 [1034]12 [6]E15 [8]E331 min
UNS
N07080
solution + stabilize + precipitation harden135 000 [930]90 000 [620]20
UNS
N09925F
solution + precipitation harden140 000 [965]105 000 [724]182538, Rc max
UNS
N09925G
solution + precipitation harden140 000 [965]110 000 [758]182538, Rc max

Note:

A. The supplier shall demonstrate that the material will meet fully heat-treated properties after full heat treatment in accordance with Table 2.
B. Forgings.
C. Up to 2.50 in. [63.5 mm], exclusive.
D. 2.50 to 4.00 in. [63.5 to 101.6 mm], exclusive.
E. These values apply for tension specimens machined tangentially from near the center of large disk forgings over 50 in.2 [3225.8 mm2] in cross section or radially from rings 3 in. [76.2 mm] or more in thickness.
F. Cold worked, solution annealed and aged, 0.625 in. [15.9 mm] to 3 in. [76.2 mm], inclusive.
G. Hot worked, solution annealed and aged, 1 in. [25.4 mm] or over.

Stress Rupture Requirements

AlloyHeat TreatmentTest
Treatment
F(C)
Stress, psi
(MPa) B
Minimum HoursElongation in 2 in. or 50mm(or 4D), min,%
UNS
N07750 Type 1
N07750 Type 1 solution at 2100°F (114900) + stabilize + precipitation 1350 45
000
100 5 (3 if hours exceed
harden
1350
(732)
45000
(310)
1005 (3 if hours exceed
harden 136)
UNS
N07718
solution + precipitation harden.1200
(649)
100000
(690)
235
UNS
N07080
solution + stabilize + precipitation harden.1400
(760)
47000 (325)233.5
UNS
N09925A
solution + precipitation harden.

Number of Tests

Chemical Analysis—One test per lot.
Tension—One test per lot,
Hardness—One test per lot.
Stress-Rupture-One test per lot.

Test Methods

Determine the chemical composition and mechanical and other properties of the material as enumerated in this specification, in case of disagreement, in accordance with the following methods:

TestASTM Desigination
Chemical AnalysisE1473
TensionE8/E8M
Rounding ProcedureE29
Stress-ruptureE139
Hardness ConversionE140

For purposes of determining compliance with the specified limits for requirements of the properties listed in the following table, an observed value or a calculated value shall be rounded in accordance with the rounding method of Practice E29

TestRounded Unit for Observed Or Calculated Value
Chemical composition,
Nearest unit in the last righthand place of figures of the
pressed in decimals), specified limit. If choices
and hardness
Nearest unit in the last righthand place of figures of the
pressed in decimals), specified limit. If choices
and hardness are possible, as when the digits dropped are exactly a 5 or a 5
followed only by zeros, choose the one ending in an even digit, with zero
defined as
an even digit.
Tensile strength and yield strengthNearest 1000 psi (6.9 MPa)
ElongationNearest 1%
Rupture life1h

Certification

When specified in the purchase order or contract, a producer’s or supplier’s certification shall be furnished to the purchaser that the material was manufactured, sampled, tested, and inspected in accordance with this specification and has been found to meet the requirements. When specified in the purchase order or contract, a report or the test results shall be furnished.

Referenced Documents

StandardDocuments
B880Specification for General Requirements for Chemical Check Analysis Limits for
Nickel, Nickel Alloys and Cobalt Alloys
E8/E8MTest Methods for Tension Testing of Metallic Materials
E29Practice for Using Significant Digits in Test Data to Determine Conformance with
Specifications
El39Test Methods for Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of
Metallic Materials
E14Hardness Conversion Tables for Metals Relationship Among Brinell Hardness,
Vickers
Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, Scleroscope
Hardness, and Leeb Hardness
E1473Test Methods for Chemical Analysis of Nickel, Cobalt and High-Temperature Alloys