Engineered Castings for Severe Thermal Environments – ASTM A297 HK

ASTM A297 HK is one of the true workhorse alloys for extreme-temperature service. With excellent high-temperature strength and oxidation resistance, HK is widely specified for stressed structural components operating at temperatures up to 1150 °C (2100 °F).

Its austenitic microstructure delivers outstanding stability under thermal cycling and sustained load, making it ideal for furnace hardware and high-heat process equipment.HK also offers strong resistance to hot gases — including sulphur-bearing atmospheres — in both oxidising and reducing conditions.This versatility is why it performs reliably in air, ammonia, hydrogen, and even molten salt environments.

HK provides one of the most economical combinations of strength and surface stability at temperatures up to and above 1035 °C (1900 °F), accounting for almost half of global heat-resistant alloy tonnage.It can be used structurally up to 1150 °C (2100 °F), although it is not recommended where severe thermal shock is a dominant factor.

Typical Applications

 Furnace grates, rails, and supports

 Radiant tubes and reformer tubes

 Multi-hearth furnace components (rabble arms, hearth hardware)

 Kiln furniture and heat-treatment fixtures

 Furnace door arches and stack dampers

 Steam methane reformer tubing

 Ethylene pyrolysis tubing

 Gas turbine components

 Cement kiln nose segments

 Retorts, brazing fixtures, and radiant hardware

In these environments, creep resistance, rupture strength, thermal fatigue performance, and corrosion resistance at temperature are critical — and this is where HK excels.

Its proven balance of mechanical strength and surface stability makes ASTM A297 HK a preferred choice for long-term, high-temperature structural service.

Learn more about our high-temperature alloy capability at www.malabou.com