COOLING METHOD FOR PREVENTING QUENCHED CRACK AT QUENCHING TIME WHILE SHIFTING BAR STEEL

摘要

PROBLEM TO BE SOLVED: To provide a cooling method with which quenched crack can be prevented in a shifting quench for bar steel having long length.;SOLUTION: The cooling method for preventing the quenched crack at the quenching time while shifting the bar steel, is characterized in, that in the shifting quench for bar steel having long length, the cooling term (tc) before the center temperature of the steel material reaches an Ms point, is set so as to become high at most the surface temperature of the steel material when the center temperature of the steel material reaches the Ms point without delaying the time (t) till reaching the center temperature of the steel material. Wherein without delaying the time (t) till reaching the center temperature of the steel material means that being cooling time tc in order to use the maximum recovered heat on the surface temperature of the steel material.;COPYRIGHT: (C)2011,JPO&INPIT