Compared with casehardened steel, the outstanding merit of through-hardened steel is that the heat treatment thereof is simple, wherein extra heat treatment can be re-made during subsequent mold repair process. It’s demerit is that crackles can easily occur, especially for large-scale molds.

The influence of heat treatment on erosion resistance of erosion-resistance steel is enormous, especially such influence as tempering temperature, method and times as well as distribution of precipitated carbide. When tempering temperature is lower than 400 celsius degree, small amount of carbide will be precipitated, which may reduce the residual stress of martensite, whereas produce no impact on erosion resistance. If the tempering temperature is within the range of brittle temperature of second type of tempering, the erosion resistance property will be obviously reduced. The maximum erosion happens under the temperature about 50 celsius degree higher than the aforementioned brittle temperature, when the precipitated carbide begins to increase and the chorme content around the carbide reduces, whereby erosion will occur to these areas. The higher the tempering temperature, the higher the chrome content around the carbide through transference, and the erosion resistance property thereby will be improved.