Steel for a plastic molding die

Abstract

To provide a steel for plastic molding die which possesses enough hardness, wear resistance and corrosion resistance, and is excellent in high-precision processability and mirror polishing properties. The steel for a plastic molding die contains not more than 0.80 wt% C, not less than 0.01 wt% and less than 1.40 wt% Si, not less than 0.05 wt% and not more than 2.0 wt% Mn, not less than 0.005 wt% and not more than 1.00 wt% Ni, not less than 13.0 wt% and not more than 20.0 wt% Cr, not less than 0.20 wt% and not more than 4.0 wt% Mo + 1 / 2 W, not less than 0.01 wt% and not more than 1.00 wt% V, not less than 0.36 wt% and not more than 0.80 wt% N, not more than 0.02 wt% O, not more than 0.80 wt% A1, and the remainder substantially including Fe and unavoidable impurities.

Description

technical field [0001] The invention relates to a steel for plastic forming molds. Background technique [0002] In recent years, various plastic molded products are used in various fields. For example, a plastic molded product is generally molded into a desired shape using a plastic molding die such as an injection molding die. [0003] However, fillers such as glass fibers are often added to plastic molding materials from the viewpoint of improving the strength of molded products by adding the main component resin. Such additives will wear the mold, so that the dimensional accuracy of the obtained plastic molded product will decrease, resulting in a reduction in the life of the mold. [0004] In addition, plastic molding materials generate corrosive gases due to decomposition of resin during kneading and the like. If such corrosive gas is compressed in the mold to high temperature and high pressure, the mold will be corroded, and the surface roughness and flashing of th...

AI Technical Summary

Problems solved by technology

[0009] However, in the alloy disclosed in Patent Document 1, coarse precipitated carbonitrides are likely to be formed in the manufacturing stage, and due to the difference in hardness between the generated coarse precipitated carbonitrides and the parent phase, processing unevenness occurs during engraving, etc. The problem of poor finishing accuracy