In industrial producing process, mould steel is the major material in mould industry. Working life, components' accuracy, quality, appearance performance of the mould has close relationship with not only its design technique, manufacturing accuracy, machine precision and operation, but also with whether the correct technology of heat treatment being carried out.
The heat treatment quality and usability of the mould are generally judged by its hardness. Hardness is an important performance index of mould material and finished mould. The force condition of mould is complex while working, for example, hot-working mould generally suffers alternating stress in alternating temperature field. Therefore, it should have the ability that prevents the mould from changing into soft or plastic state, and keeps its shape, size and accuracy the same in long time working environment. Generally, the cold-working mould chooses finished mould hardness value of 59-60HRC, while the hot-working mould chooses finished mould hardness value of about 48HRC.Abrasive resistance is an important performance index of finished mould. When parts form, metal and mould cavity surface would be in relative motion, abrasing mould cavity surface and making mould size, shape, accuracy, and surface roughness changes and lose efficacy. Mould abrasive resistance is generally determined by its heat treatment, especially superficial heat treatment. Judging the abrasive resistance is mainly based on hardness(hardness tester).