METHOD OF MAKING POWDER OF FERRUM-NICKEL BASE ALLOYS Russian patent published in 1995 - IPC

FIELD: powder metallurgy. SUBSTANCE: method comprises steps of cooling a ferrum-nickel base alloy, containing 0.5% of carbon, the balance-ferrum and having grains (0.1-0.5)mm with unequal axis, up to a temperature, lower, than a point of its direct martensite conversion γ-α with a rate, more, than a critical one and being higher, than 12 C/s. For the alloy 50H25 a temperature of the direct martensite conversion is equal to (-48)C. The cooling process is being performed up to a temperature, lower, than the above mentioned temperature, for example up to liquid nitrogen temperature. Then the alloy is being heated in a salt bath up to a temperature of termination of reverse a-γ conversion, and it is being cooled successively in water and in liquid nitrogen with use of a detergent upon cooling the alloy in water. EFFECT: enhanced efficiency of disintegration due to higher degree of previous embrittlement. 1 cl, 1 tbl