ON THE MECHANICAL PROPERTIES OF STEEL N26T

strength. The high strength of these steels is due mainly to phase strain hardening during the direct and reverse martensitic transformations. Consequently, the more complete the martensitic y ÷ ~ transformation (the more austenite that is transformed to martensite), the higher the strength. It is known [i, 2] that a limited quantity of martensite is formed during the y + transformation in several Ni--Ti steels hardened by phase strain hardening, but increasing the number of y ÷ ~ ÷ y cycles does not increase the amount of martensite transformed. In this connection a study of heat treatments that increase the quantity of transformed martensite is of great practical interest. The purpose of this work was to determine the possibility of increasing the completeness of the martensitic transformation as the result of aging before repeated cold treatment (with repetition of the y ~ ~ cycle). The study was conducted with steel N26T (0.05% C, 26% Ni, 1-1.2% Ti). Forged bars