Method for producing a steel part and corresponding steel part

Abstract

A method for producing a steel part and corresponding steel part includes casting a steel having a composition comprising: 0.10%≤C≤0.35%, 0.8%≤Si≤2.0%, 1.8%≤Mn≤2.5%, P≤0.1%, 0%≤S≤0.4%, 0%≤Al≤1.0%, N≤0.015%, 0%≤Mo≤0.4%, 0.02%≤Nb≤0.08%, 0.02%≤Ti≤0.05%, 0.001%≤B≤0.005%, 0.5%≤Cr≤1.8%, 0%≤V≤0.5%, 0%≤Ni≤0.5%, to obtain a semi-product, hot rolling the semi-product at a hot rolling starting temperature higher than 1000° C. and cooling the product through air to room temperature to obtain a hot rolled steel part having a microstructure consisting of 70% to 90% of bainite, 5% to 25% of M/A compounds and at most 25% of martensite. The bainite and the M/A compounds contain retained austenite such that the total content of retained austenite in the steel is comprised between 5% and 25%, the carbon content of the retained austenite being comprised between 0.8% and 1.5%.