The classic corrosion analysis of mold corrosion and rust

The classic corrosion analysis of mold corrosion and rust, after the heat treatment of the mold, corrosion and rust scar appear on the surface, the mold is prone to crack after quenching, and the mold is scrapped. The mold is rusted during use, and the plastic mold is rusted for a long time. The reasons and measures to prevent mold rust were analyzed and summarized. The mold is prone to crack after quenching, which causes the mold to be scrapped. The crack in the mold is not uniform with the final spheroidized structure of the mold, the spheroidization is imperfect, and the structure is related to the network, band and chain carbide. The cause may be: 1.

There is serious carbide segregation in the original structure of the die steel material. 2. The forging process is not good, such as the forging heating temperature is too high, the deformation amount is small, the stop forging temperature is high, the cooling speed after forging is slow, etc., so that the forged structure is coarse and there are mesh, band and chain carbides present, so that the ball It is difficult to eliminate during annealing. 3. The spheroidizing annealing process is not good.

If the annealing temperature is too high or too low, the isothermal annealing time is short, etc., the spheroidizing annealing may be uneven or spheroidized. The solution should generally be based on the working conditions of the mold, the production batch and the toughness of the material itself, and try to choose a good quality mold steel material. Improve the forging process or use normalizing heat treatment to eliminate the non-uniformity of the network and chain carbides and carbides in the raw materials. High-carbon die pipe fitting mould steel with severe segregation of carbides that cannot be forged can be subjected to solution heat treatment.