Fabrication of very high strength steel sheet by hot and cold rolling followed by a restoration heat treatment, notably for motor vehicle applications

摘要

The fabrication of a high strength steel sheet consists of: (a) hot rolling a high strength steel of which the tensile strength (Rm) is greater than or equal to 450 MPa; (b) cold rolling the hot rolled sheet with a rate of reduction between 10 and 20%; (c) submitting the cold rolled sheet to a restoring heat treatment at a temperature below the austenite temperature (Ac3). An Independent claim is also included for the high strength steel sheet produced.