Parts with a bainitic structure having high strength properties and manufacturing process

• Main Authors: Resiak, Bernard, Perrot-Simonetta, Marie-Thérèse, Voll, Ulrich
• Format: Patent
• Language: English
• Published: 29.10.2024
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present invention provides a part having a composition including, with the contents being expressed in weight-percent, 0.10≤C≤0.30, 1.6≤Mn≤2.1, 0.5≤Cr≤1.7, 0.5≤Si≤1.0, 0.065≤Nb≤0.15, 0.0010≤B≤0.0050, 0.0010≤N≤0.0130, 0≤Al≤0.060, 0≤Mo≤1.00, 0≤Ni≤1.0, 0.01≤Ti≤0.07, 0≤V≤0.3, 0≤P≤0.050, 0.01≤S≤0.1, 0≤Cu≤0.5, 0≤Sn≤0.1. A balance of the composition includes iron and unavoidable impurities resulting from the production method. The microstructure includes, in surface proportions, from 100% to 70% bainite, less than 30% residual austenite, and less than 5% ferrite. A manufacturing method is also provided.