HIGHLY ACCURATE CARBURIZING AND QUENCHING METHOD, AND METHOD FOR DETERMINING CARBURIZING AND QUENCHING CONDITION

摘要

PROBLEM TO BE SOLVED: To suppress the variance of the shape strain generated in the carburizing and quenching of steel.;SOLUTION: The cooling speed distribution of steel and/or the carbon content distribution in steel in the depth direction is determined so that a curve 60 of the martensitic transformation point to the depth of steel is steeper than a curve 62 of the temperature in cooling steel to the steel depth when the curve 62 is superposed on the curve 60. Under this condition, the martensitic transformation is advanced from the inner side of steel to the face side. When the martensitic transformation is advanced from the inner side of steel to the face side, the variance in the shape strain during the hardening is suppressed.;COPYRIGHT: (C)2002,JPO