High strength, tough alloy steel

摘要

A high strength, tough alloy steel is formed by heating the steel to a temperature in the austenite range (1000 DEG -1100 DEG C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other substitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below 300 DEG C.) and reforms to a stable film after austenite grain refinement.