Method for manufacturing glass molding die

Abstract

A method for manufacturing a glass molding die includes forming a substrate by hardening a steel material containing 0.3 wt % or more and 2.7 wt % or less of carbon and 13 wt % or less of chromium, and further containing at least one additive selected from 0.5 wt % or more and 3 wt % or less of molybdenum, 0.1 wt % or more and 5 wt % or less of vanadium, and 1 wt % or more and 7 wt % or less of tungsten, and then tempering the steel material at a temperature of 400° C. or higher and 650° C. or lower, forming a surface coating layer composed of an amorphous Ni—P alloy on the surface of the substrate, and heating the surface coating layer thereby rendering the surface coating layer an eutectic structure composed of Ni and Ni 3 P.

1 . A method for manufacturing a glass molding die, comprising:
 forming a substrate by hardening a steel material containing 0.3 wt % or more and 2.7 wt % or less of carbon and 13 wt % or less of chromium, and further containing at least one additive selected from 0.5 wt % or more and 3 wt % or less of molybdenum, 0.1 wt % or more and 5 wt % or less of vanadium, and 1 wt % or more and 7 wt % or less of tungsten, and then tempering the steel material at a temperature of 400° C. or higher and 650° C. or lower;   forming a surface coating layer composed of an amorphous Ni—P alloy on the surface of the substrate; and   heating the surface coating layer thereby rendering the surface coating layer an eutectic structure composed of Ni and Ni 3 P.   
   
   
       2 . The method for manufacturing a glass molding die according to  claim 1 , wherein the surface coating layer is formed by electroless plating containing Ni and P, Ni, P and B or Ni, P and W, and the temperature of the heat treatment is greater than or equal to a glass molding temperature. 
   
   
       3 . A method for manufacturing a glass molding die, comprising:
 forming a substrate by hardening a steel material containing 0.3 wt % or more and 2.7 wt % or less of carbon and 13 wt % or less of chromium, and further containing at least one additive selected from 0.5 wt % or more and 3 wt % or less of molybdenum, 0.1 wt % or more and 5 wt % or less of vanadium, and 1 wt % or more and 7 wt % or less of tungsten, and then subjecting the steel material to subzero treatment;   forming a surface coating layer composed of an amorphous Ni—P alloy on the surface of the substrate; and   heating the surface coating layer thereby rendering the surface coating layer an eutectic structure composed of Ni and Ni 3 P.   
   
   
       4 . The method for manufacturing a glass molding die according to  claim 3 , wherein the surface coating layer is formed by electroless plating containing Ni and P, Ni, P and B or Ni, P and W, and the temperature of the heat treatment is greater than or equal to a glass molding temperature.