HAYNES 244 alloy – a new 760 ∘C capable low thermal expansion alloy

Abstract

HAYNES® 244TM alloy is a new 760∘C capable, high strength low thermal expansion (CTE) alloy. Its nominal chemical composition in weight percent is Ni – 8 Cr – 22.5 Mo – 6 W. Recently, a first mill-scale heat of 244 alloy was melted by Haynes International, and processed to various product forms such as re-forge billet, plate, and sheet. This paper presents key attributes of this new alloy (CTE, strength, low-cycle fatigue performance, oxidation resistance, thermal stability) as they pertain to the intended use in rings and seals of advanced gas turbines.