ArcelorMittal S.A.
A METHOD OF MANUFACTURING MARTENSITIC STEEL AND A MARTENSITIC STEEL THEREOF

Abstract:

A martensitic steel including the following elements, expressed in percentage by weight 0.1%.ltoreq.C.ltoreq.0.4%; 0.2%.ltoreq.Mn.ltoreq.2%; 0.4%.ltoreq.Si.ltoreq.2%; 0.2%.ltoreq.Cr.ltoreq.1%; 0.01%.ltoreq.Al.ltoreq.1%; 0%.ltoreq.S.ltoreq.0.09%; 0%.ltoreq.P.ltoreq.0.09%; 0%.ltoreq.N.ltoreq.0.09%; and can contain one or more of the following optional elements 0%.ltoreq.Ni.ltoreq.1%; 0%.ltoreq.Cu.ltoreq.1%; 0%.ltoreq.Mo.ltoreq.0.1%; 0%.ltoreq.Nb.ltoreq.0.1%; 0%.ltoreq.Ti.ltoreq.0.1%; 0%.ltoreq.V.ltoreq.0.1%; 0.0015%.ltoreq.B.ltoreq.0.005%; 0%.ltoreq.Sn.ltoreq.0.1%; 0%.ltoreq.Pb.ltoreq.0.1%; 0%.ltoreq.Sb.ltoreq.0.1%; 0%.ltoreq.Ca.ltoreq.0.1%; the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel having microstructure by area percentage including cumulative presence of residual austenite and bainite between 0% and 25%, the remaining microstructure being martensite at least 70%, and with an optional presence of ferrite between 0% and 10%.