STEEL SHEET FOR DIE QUENCHING HAVING EXCELLENT HOT PUNCHABILITY AND METHOD FOR PRODUCING MEMBER BY DIE QUENCHING PROCESS

摘要

PROBLEM TO BE SOLVED: To provide a steel sheet having excellent punchability in which the height of a bur generated upon hot punching in a die quenching process is low, and to provide a member produced by a die quenching process.;SOLUTION: The steel sheet for die quenching having excellent hot punchability is a steel sheet having a composition comprising, by mass, 0.10 to 0.19% C, 0.05 to 0.5% Si, 1.0 to 1.8% Mn, ≤0.03% P, 0.002 to 0.020% S, 0.015 to 0.07% Al, 0.0025 to 0.010% N and 0.02 to 0.06% Ti, and further comprising one or more selected from, by mass, 0.15 to 1% Cr and 0.1 to 0.5% Mo, and the balance iron with inevitable impurities, the steel for die quenching having excellent hot punchability is characterized in that after the heating of the steel sheet to an austenitic single phase region, in a range at least from the outermost surface to a depth of 100 μm of the steel sheet, TiN is scattered, and the average of the length of the side longest in TiN is 0.1 to 1 μm.;COPYRIGHT: (C)2010,JPO&INPIT