ASTM A638 Bolts
ASTM A638 is the Standard Specification for Precipitation Hardening Iron Base Superalloy Bars, Forgings, and Forging Stock for High-Temperature Service. This specification covers alloys with mechanical properties developed by suitable solution treating and precipitation hardening treatments.Based on design, service conditions, mechanical properties, and elevated temperature characteristics ASTM A638 covers two grades of iron based alloys.
ASTM A638 Bars, Forgings, Forging Stock Manufacturers & Suppliers
Products manufactured under ASTM A638 specification are furnished in three different conditions viz Hot Finished, Solution Annealed, Solution Annealed and precipitation treated.In addition to the requirements of this specification, all requirement of ASTM A 484/A 484M (Specification for General Requirements for Stainless Steel Bars, Billets, and Forgings) Shall Apply.
This Specification Covers three types viz Grade 660 Type 2 and Grade 660.
ASTM A638 Bolts – TABLE OF CONTENT
ASTM A638 Chemical Composition
|Grade 660 (UNS S66286)’1||Grade 662 (UNS S66220)’1|
|Ladle Analysis Range, %||Check Analysis Over or Under||Ladle Analysis Range, %||Check Analysis Over or Under|
|Carbon||0.08 max||0.01 over||0.08 max||0.01 over|
|Manganese||2.00 max||0.04 over||1.50 max||0.04|
|Silicon||1.00 max||0.05 over||1.00 max||0.05|
|Phosphorus||0.040 max||0.005 over||0.040 max||0.005 over|
|Sulfur||0.030 max||0.005 over||0.030 max||0.005 over|
|Copper||—||—||0.50 max||0.03 over|
|Aluminum||0.35 max||0.05 over||0.35 max||0.05 over|
|Boron||0.0010-0.010||0.0004 under 0.001 over||0.0010-0.010||0.0004 under 0.001 over|
A New designation established in accordance with Practice E 527 and SAE J1086.
ASTM A638 Mechanical Properties
|Grade 660||Grade 662 (bars)||Grade 662 (forgings)-4|
|Heat treatment®||solution + precipitation harden||solution + precipitation harden||solution + precipitation harden|
|TENSILE STRENGTH, MIN:|
|psi||130 000||130 000||125 000|
|Yield strength CO.2% offset), min: psi||85 000||85 000||80 000|
|Elongation in 4D min, %||15||15||15|
|Reduction of area min, %||18||18||18|
|Brinell hardness||248 min||248 min||248 min|
AThe elongation of tensile specimens machined tangentially from near the center of large disk forgings over 50 in.2 [320 cm2] in cross section may be as low as 10%. The reduction of area may be as low as 12%.B Refer to Table 3 of heat treatment.
ASTM A638 Stress-Rupture Requirements
|660||solution + precipitation harden||1200||||65 000||||23||3|
|662||solution + precipitation harden||1200||||60 000||[4151||15||3|
A Refer to Table 2 for details of heat treatment.
fiTest specimens meeting minimum requirements may be overloaded to produce rupture in a reasonable and practical time period.
ASTM A638 Heat Treatment
|Grade||Solution Treatment||Precipitation Hardening Treatment”4|
|660 Type 1||1650 ± 25°F 900 ± 15°C], hold 2 h, oil or water quench||1300 to 1400°F [705 to 760oC], hold 16 h, air cool or furnace cool|
|660 Type2||1800 ± 25°F 980 ± 15°C], hold 1 h, oil or water quench||1300 to 1400°F [705 to 760°C], hold 16 h, air cool or furnace cool|
|662||1750 to 1900°F 955 to 1040°C], hold 1 h, min, oil or water quench||1250 to 1400°F [675 to 760°C1, hold 5 h, min, slow cooling in 5 h, min to 1200 ± 15°F [650 ± 10°C1, hold 20 h, min, air cool or furnace cool|
A Times refer to the minimum time material is required to be at temperature.
Related ASTM Specification
ASTM A1082 / A1082M – 16 : Standard Specification for High Strength Precipitation Hardening and Duplex Stainless Steel Bolting for Special Purpose Applications
ASTM A1014 / A1014M – 16 : Standard Specification for Precipitation-Hardening Bolting (UNS N07718) for High Temperature Service
ASTM F2281 : Standard Specification for Stainless Steel and Nickel Alloy Bolts, Hex Cap Screws, and Studs, for Heat Resistance and High Temperature Applications Designation
ASTM A453 / A453M – 16 : Standard Specification for High-Temperature Bolting, with Expansion Coefficients Comparable to Austenitic Stainless Steels
ASTM B637 – 15 : Standard Specification for Precipitation-Hardening and Cold Worked Nickel Alloy Bars, Forgings, and Forging Stock for Moderate or High Temperature Service
ASTM B564 – 15 : Standard Specification for Nickel Alloy Forgings
ASTM A962 / A962M – 16a : Standard Specification for Common Requirements for Bolting Intended for Use at Any Temperature from Cryogenic to the Creep Range
ASTM F467 – 15 : Standard Specification for Nonferrous Nuts for General Use
ASTM F468 – 15 : Standard Specification for Nonferrous Bolts, Hex Cap Screws, Socket Head Cap Screws, and Studs for General Use