Patent ID: 6699333
Filing Date: 2004-03-02
Classification: C21D,C22C,C23C,F02M

Abstract:
In a carburized steel composition formed from a carburizing steel composition comprising, by weight:0.06% to 0.18% of C; 0.5% to 1.5% of Si; 0.2% to 1.5% of Cr; 1% to 3.5% of Ni; 1.1% to 3.5% of Mo; 0.37% to 2% Cu; and: at most 1.6% of Mn; and/or at most 0.4% of V; and/or at most 4% of Co; balanced by iron and residual impurities; the improvement characterized by the amounts of Ni, Mn, Cu, Co, Cr, Mo and V in said carburizing steel composition, expressed by weight, satisfying the following relationships: 2.5&lE;Ni+Mn+1.5Cu+0.5Co&lE;5â€ƒâ€ƒ(1) 2.4&lE;Cr+Mo+V&lE;3.7â€ƒâ€ƒ(2); and characterized in that said carburized steel composition allows to maintain a superficial hardness of the carburized layer of 650 to 780 Vickers hardness at a temperature above 250Â° C.