γ-α-γ-martensitic transitions influence on the martensite decomposition of quenched steel

摘要

The crystalline structure changes of the Fe - 24,5 wt.% Ni - 0,5 wt. % C alloy martensite as a result of annealing after cyclic y-a-y- martensitic transitions were investigated using the X-ray method in single crystal specimens. Resulting from carbon extraction from a-solid solution acceleration, the martensite lattice parameters ratio (c/a) have reduced during the heating up to 100°Cand partially tempered martensite with reduced carbon content down to 0,25wt.% was formed. The intensification of carbon martensite decomposition as a consequence of γ-α-γ- transitions is associated with the influence of crystalline structure de fects forming during the direct y-a and the reverse a-y transitions.