METHOD FOR MANUFACTURING DIE, METHOD FOR MANUFACTURING STEEL FOR DIE, AND METHOD FOR MANUFACTURING DIE USING STEEL FOR DIE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a die of which dimensional change occurring after heat treatment is relatively small, a method for manufacturing a steel for the die and a method for manufacturing the die using the steel for the die.;SOLUTION: The method for manufacturing the die includes the following steps: a steel having a prescribed composition is cooled from a first quenching temperature T_q1 at a first cooling rate C₁ of ≥12°C/min; the steel is tempered in such a way that a first tempering index λ₁ becomes larger than a tempering index of secondary hardening peak λ_peak1and a tempering index of dimensional change rate peak λ_peak2; the above steel is then rough worked and formed into the die having a prescribed shape; the die is cooled from a second quenching temperature T_q2 at a second cooling rate C₂ of ≥12°C/min; and the above die is tempered in such a way that a second tempering index λ₂ becomes smaller than the tempering index of dimensional change rate peak λ_peak2 and a dimensional change rate at the second tempering index λ₂ becomes within a range of ±0.05% of a dimensional change rate at the first tempering index λ₁. The method for manufacturing the steel for the die and the method for manufacturing the die using the steel for the die are also provided.;COPYRIGHT: (C)2009,JPO&INPIT