ASTM A522 – Forged or Rolled 8 and 9% Nickel Alloy Steel Flanges, Fittings, Valves, and Parts for Low-Temperature Service

This specification covers 8 and 9 % nickel-alloy steel forged or rolled flanges, fittings, valves, and parts intended for use in welded pressure vessels for low-temperature service. The specification is applicable to forgings with maximum section thickness of 75 mm in the double normalized and tempered condition and 125 mm in the quenched and tempered condition. Forgings under this specification are intended for service at operating temperatures not lower than -196 °C for Type I or -170 °C for Type II or higher than 121 °C.

Chemical Compositions  (max, %)

ElementsType IType II

Heat treatment

  • Quenched and Tempered
  • Double Normalized and Tempered
  • Stress relieving

Tensile Requirements at Room Temperature

Tensile strength, min, MPa: 690

Yield strength, min, (0.2 % off-set), MPa: 515

Elongation in 2 in. [50mm], min, %: 22

Reduction of area, min, %: 45

Charpy V-Notch Lateral Expansion Requirements For Standard Size [10 X 10 mm] Specimens

TypeLateral expansion , mmTemperature °CReport absorbed energy and % shear fracture

If the lateral expansion result from one Charpy impact specimen falls below 0.015 in. [0.38 mm], but not less than 0.25 mm, and the average test result equals or exceeds 0.38 mm, then one retest of three additional specimens may be made. The lateral expansion obtained from each of the three retest specimens shall equal or exceed 0.38 mm.