Manufacturing methods and carburizing quenching member of carburizing and quenching member

摘要

PROBLEM TO BE SOLVED: To provide a carburized and quenched member which has excellent fatigue strength and shape precision, and to provide a production method therefor.;SOLUTION: The member consists of steel containing, Fe as the main component, and containing, by weight, 0.12 to 0.22% C, 0.4 to 1.5% Si, 0.25 to 0.45% Mn, 0.5 to 1.5% Ni, 1.3 to 2.3% Cr, 0.001 to 0.003% B, 0.02 to 0.06% Ti, 0.02 to 0.12% Nb, and 0.005 to 0.05% Al, and in which those contents are controlled cluing cooling from 900°C to a room temperature at a fixed rate. Bainite is not formed at a cooling rate of at least ≤0.1°C/sec, and ferrite is not formed at a cooling rate of at least ≥12°C/sec. This member is subjected to carburizing treatment in a reduced pressure carburizing atmosphere, or in a carburizing atmosphere essentially consisting of an inert gas a under ordinary pressure, so that a carburized layer in which surface carbon concentration reaches 0.6 to 1.5 mass% is formed on the member, and gas quenching is performed thereto.;COPYRIGHT: (C)2003,JPO