Chemical Composition
Grade Symbol |
UNS Number |
Alloy |
Elements |
Composition % |
F22 Class 3 |
K21590 |
chromium-molybdenum |
Carbon |
0.05 - 0.15 |
Manganese |
0.30 - 0.60 |
Phosphorus |
0.040 |
Sulfur |
0.040 |
Silicon |
0.50 |
Chromium |
2.00 - 2.50 |
Molybdenum |
0.87 - 1.13 |
Mechanical Properties
Property | Value |
Tensile Strength, min, ksi [MPa] |
75 [515] |
Yield Strength, min, ksi [MPa] |
45 [310] |
Elongation in 2 in. [50mm] or 4D, min, % |
20 |
Reduction or Area, min, % |
30 |
Brinell Hardness Number, HBW |
156-207 |
Heat Treatment
After hot working, forgings shall be cooled to a temperature below 1000 °F [538 °C] prior to heat treating in accordance with the requirements.