HIGH-CARBON STEEL SHEET FOR PRECISION-BLANKED PARTS, AND PRECISION-BLANKED PARTS

摘要

PROBLEM TO BE SOLVED: To provide a high-carbon steel sheet which has both of a precision-blanking property and mechanical characteristics after having been heat-treated, and is suitable for manufacture of machine parts made of a steel with high hardness, such as a bearing and a gear.;SOLUTION: The steel sheet has a chemical composition comprising, by mass, 0.7-0.9% C, 0.5% or less Si, 0.2-1.2% Mn, 0.02% or less P, 0.01% or less S, 0.1-1.0% Cr and the balance substantially Fe; has a structure consisting of the carbides which has the maximum length of 5.0 μm or less, has a spheroidized rate of 90% or higher and contains the spheroidized carbides with a particle size of 2.0 μm or larger in an amount of two or less pieces per 100 μm² when the cross section is observed with a microscope, and of equiaxial ferrite; and further has a hardness of 200 HV or lower in the cross section.;COPYRIGHT: (C)2006,JPO&NCIPI