Engineering Steel with a Bainitic Structure, Forged Parts Produced Therefrom and Method for Producing a Forged Part

摘要

An engineering steel including (in wt.-%) up to 0.25% C, up to 0.45% Si, 0.20-2.00% Mn, up to 4.00% Cr, 0.6-3.0% Mo, 0.004-0.020% N, up to 0.40% S. 0.001-0.035% Al, 0.0005-0.0025% B, up to 0.015% Nb, up to 0.01% Ti, up to 0.10% V, up to 1.5% Ni and up to 2.0% Cu, remainder iron and unavoidable impurities, wherein the Al content % Al, the Nb content % Nb, the Ti content % Ti, the V content % V and the N content % N meet the following condition: % Al/27+% Nb/45+% Ti/48+% V/25% N/3.75. The steel has a yield strength of at least 750 MPa, a tensile strength of at least 950 MPa and a structure having at least 80 vol.-% bainite and a total of a maximum of 20 vol.-% of retained austenite, ferrite, perlite and/or martensite.