PURPOSE: To provide the method for manufacturing a mold for heat resistant glass improved in high temp. strength, in which the generation of heat cracks is suppressed and.improved in the service life of the molding die.
CONSTITUTION: This method for manufacturing a molding die for heat resistant glass is characterized by subjecting heat resistant steel constituted of the following compsn. and subjected to ingot-making by an electro-slag remelting method to die forging in the temp. range of 1050 to 1150°C, hardening it at 900 to 1000 C and furthermore executing tempering at 650 to 750°C. The heat resistant steel is a one contg., by weight, 0.1 to 0.4% C, 0.05 to 2.0% Si, 0.1 to 2.0% Mn, 10.0 to 15.0% Cr, 0.7 to 1.2% W, 0.7 to 1.2% Mo and 0.05 to 2.0% V, furthermore contg. at least one kind from among 0.001 to 0.10% B, 0.01 to 0.5% Nb, 0.5 to 1.0% Ni and 0.1 to 6.0% Co and the balance Fe with inevitable impurities.
SATO TOMOHIKO
WADA TAKAO
