Patent ID: 6360936
Filing Date: 2002-03-26
Classification: B32B,C22C,F41H,Y10T

Abstract:
A method of manufacturing composite sheet steel of maraging steel, wherein the composite sheet steel comprises an outer layer and an inner layer, wherein the outer layer is harder than the inner layer and the inner layer is more tenacious than the outer layer, the method comprising the steps of:producing steel of the inner layer with a chemical composition containing in percent by weight: C&lE;0.01, Si&lE;0.1, Mn&lE;0.1, P&lE;0.005, S&lE;0.005, Cu&lE;0.1, Mo 4.80 to 5.20, Ni 17.5 to 18.5 , Cr&lE;0.1, Ti 0.55 to 0.70, Co 8.0 to 9.0, with the remainder being Fe and contaminants resulting from the manufacturing process; and producing steel of the outer layer, with purification in a zone melting process by removing aluminum, added to suppress formation of oxides other than aluminum oxide, and oxygen bonded thereto, with a chemical composition containing in percent by weight: C&lE;0.01, Si<0.1, Mn 0.02 to 0.20, P&lE;0.005, S&lE;0.005, Cu 0.01 to 0.20, Mo 4.80 to 5.20, Ni 17.5 to 18.5, Cr 0.01 to 0.20, Ti 1.80 to 1.95, Co 14.0 to 15.5, Al 0.05 to 0.15, with the remainder being Fe and contaminants resulting from the manufacturing process.