SURFACE GRAIN REFINING HOT-SHEARING METHOD AND PRODUCT OF SURFACE GRAIN REFINING HOT-SHEARING.

摘要

A surface grain refining hot-shearing method which comprises heating and keeping a steel sheet in a temperature range of Ac3 to 1400ºC to austenitize the steel sheet, setting the resulting steel sheet on a die to conduct the shearing of the sheet, and then hardening the sheared workpiece by quenching, wherein the initiation temperature of the shearing is adjusted to a temperature (ºC) falling within a range between Ar3 plus 30ºC and Ar3 plus 140ºC, Ar3 being a measured value obtained by Ar3 measurement of the steel sheet.