HIGH PROOF STRENGTH CARBURIZED STEEL AND COMPONENT FOR MACHINE STRUCTURE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a high proof strength carburized steel and a component for machine structure having high proof strength and restraining the lowering of shock resistance and toughness.;SOLUTION: In the high proof strength carburized steel having a carburize-quenching layer formed on the surface of the steel material composed, by mass%, of 0.30-0.60% C, 2.00 to 4.00% Si, 0.10-1.50% Mn, 0.50-2.50% Ni, 0.10-2.00% Cr, 0.05-1.00% Mo and 0.05-0.50% V and the balance Fe with inevitable impurities; the carbon concentration X on the carburize-quenching layer is 0.6≤X≤0.7 mass%, and the carburizing distance δ is 0.8 mm≤δ≤1.2 mm and the segregation ratio (a) of Si is 1.00≤a≤1.30 and the residual γ quantity of the above steel material is ≤10 vol%.;COPYRIGHT: (C)2008,JPO&INPIT