Production method and forged components between the high-temperature carburizing heat produced by the method of hot-forged part for a high-temperature carburizing

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a hot-forged component for high-temperature carburization which inhibits the occurrence of duplex grain size and greatly shortens carburization time, particularly when the component is subjected to hot-temperature carburization after hot forging.;SOLUTION: A hot-rolled steel material comprising, by weight, 0.10-0.30% C, 0.05-0.50% Si, 0.30-1.50% Mn, 0.30-2.00% Cr, 0.005-0.050% Al, 0.01-0.10% Nb, 0.0080-0.0250% N, ≤0.01% V, ≤0.80% Mo if required and the balance being Fe and unavoidable impurities is heated to 1,150-1,350°C, subsequently hot-forged at a forging finishing temperature of 1,100-1,300°C so that the Nb contained in the steel substantially becomes solid solution (with number of deposited Nb of ≤0.3/μm²), cooled to 620-700°C after forging, retained at that temperature for 30 min to 5 hr, cooled to room temperature and subjected to carburization.;COPYRIGHT: (C)2005,JPO&NCIPI