How to adopt heat treatment process to reduce the deformation of die?

1. Pre heat treatment

For the precision and complex die, if the hardness requirement is not too high, the pre hardened steel of pre heat treatment can be used to pre heat treat the die steel (such as 3Cr2Mo, 3crmnnimo steel) to reach the hardness (the lower hardness is 25-35hrc, the higher hardness is 40-50hrc) when it is used, and then the die is processed and formed without heat treatment, so as to ensure the precision of the precision and complex die.

2. Quenching and tempering heat treatment

For the precision and complex mould with low requirement of matrix hardness and high requirement of surface hardness, the heat treatment after rough machining and low temperature nitriding treatment (500 ~ 550? C) after finishing can be adopted. Due to the low nitriding temperature of mould, there is no phase transformation of matrix structure. In addition, when the furnace is cooled to room temperature, the cooling stress is less and the mould deformation is smaller.

3. Use of age hardening die steel

Age hardening steel can be used for precision and complex dies. For example, PMS (1ni3mn2cua1. Mo) steel is a new type of age hardening die steel. The hardness after solution quenching at 870? C is about 30 HRC, which is convenient for machining. After the die is processed and shaped, aging heat treatment at about 500? C can obtain a high hardness of 40 ~ 45 HRC. The deformation of the die is small, and only polishing treatment is needed, which is an ideal precision re coating. Steel for miscellaneous mould.