Mold Surface Strengthening Treatment
In recent years, with the development of industry, the requirements for product quality have become increasingly strict, and the requirements for molds have become higher and higher. In particular, precision die-casting molds require a high degree of mechanical properties, and require a small amount of deformation, which is basically no longer processed after heat treatment.
(1) mold gas soft nitriding
Gas nitrocarburizing is a new chemical heat treatment process developed by liquid soft nitriding. In this process, an organic compound such as urea, formic acid amine or triethanolamine is used as a osmotic agent in a pit furnace, or an nitriding treatment is carried out by adding an additive such as ammonia and a carburizing gas.
The gas soft nitriding process has low temperature, short time, small deformation and no restriction on steel. It can significantly improve the wear resistance, fatigue, anti-seizure and abrasion of the mold cavity after treatment. In addition, it also solves the problem of toxicity of liquid soft nitriding, and has the characteristics of good working conditions, stable nitriding quality, and convenient process operation.
(2) Mold ion nitridation
Ion nitriding is a new chemical heat treatment process for improving the wear resistance, fatigue strength and corrosion resistance of mold parts. The production practice proves that the application is good on die-casting molds.
(3) mold chromizing
The chromizing of the die-casting mold can improve the hardness of the cavity (above HV1300), wear resistance, corrosion resistance, fatigue strength and high temperature oxidation resistance. For molds that are subject to intense wear, the service life can be significantly increased.
When the mold is chromized, it is heated to 950 ° C ~ 1100 ° C, and the temperature is kept for 5 h ~ 10 h to form a layer of firmly chromized layer. The thickness of the chromized layer is generally small and does not affect the size of the mold cavity.