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.
