Temperature and fancy movement of mould materials
It can be seen from the above diagram that the higher the hardness required for the material, then the quenching temperature will be higher , the toughness will be lower, and the tempering temperature will be lower.
One of the important functions of tempering is to eliminate the residual stress in quenched steel. The higher the tempering temperature is, the more thoroughly the quenching stress is eliminated and the plasticity of the steel increases. Of course, the hardness of quenched steel will also decrease. Therefore, when determining the hardness of mould materials, we should not only consider raising the hardness requirement to the maximum to prevent erosion, but should fully consider the stress problem of mould structure, and reduce the appropriate hardness value according to the actual situation. Because erosion can also be solved by surface nitriding, coating, improving gating system, adjusting die casting process and so on. On the contrary, if the stress concentration, premature mould cracking and loss will be greater.
