Overview
Grade HT is a high-temperature austenitic stainless steel casting alloy specified by ASTM A297/A297M, engineered for structural components exposed to prolonged heat and thermal cycling. With a composition typically containing 25% chromium and 35% nickel, HT offers superior resistance to oxidation, carburization, and thermal fatigue. This alloy is well-suited for furnace hardware, radiant tubes, heat-treat fixtures, and other components used in aggressive high-temperature environments. Its excellent creep strength and dimensional stability make Grade HT a reliable choice for service in petrochemical, metallurgical, and thermal processing industries.
Chemical Composition
Carbon
Manganese
2.00% Max
Silicon
2.50% Max
Phosphorus
0.04% Max
Sulfur
0.04% Max
Chromium
15.00 - 19.00%
Nickel
33.00 - 37.00%
Molybdenum
0.50% Max
Physical Properties
Tensile Strength
65 ksi Min
Elongation at 2 in
4% Min
Resources
ASTM Standard
