A METHOD OF STABILISING THE AUSTENITIC STRUCTURE OF ALLOYS AGAINST MARTENSITE TRANSFORMATION

摘要

1,211,934. Heat-treating iron alloys. DEUTSCHE EDELSTAHLWERKE A.G. Feb. 5, 1968 [March 2, 1967], No.5694/68. Heading C7A. Austenitic alloys are aged at a temperature above the martensitic transformation point to form a coherent or partly coherent precipitate whereby the Ms temperature is lowered. The ageing may be carried out between 300‹ and 900‹C. In a particular embodiment an alloy containing 30% Ni, 6% Al, balance Fe was homogenized at 1300‹C. for 16 hours, quenched, and aged at 500‹C. for 1¢ hours. By this treatment the Ms temperature was lowered from -70‹C. to below -269‹C.