How to prevent heat treatment deformation of precision molds

Update:17-05-2019
Summary:

(1) Reasonable material selection. For precision and co […]

(1) Reasonable material selection. For precision and complex molds, micro-deformed die steel with good material quality (such as air-quenched steel) should be selected; for die steel with severe carbide segregation, reasonable casting should be carried out and heat treatment should be carried out; It is impossible to cast mold steel and can perform solid solution double refining heat treatment.
(2) The design of the mold structure should be reasonable, the thickness should not be too disparate, and the shape should be symmetrical. For the mold with large deformation, the deformation law should be grasped and the machining allowance should be reserved; for large and sophisticated molds, the combined structure can be adopted.
(3) Precise heat treatment of precision and complex molds to eliminate residual stress generated during machining.
(4) Reasonably select the heating temperature and control the heating rate. For sophisticated molds, slow heating, preheating, and other balanced heating methods can be used to reduce mold heat treatment distortion.
(5) Under the condition of ensuring the hardness of the mold, pre-cooling, staged cooling quenching or warm quenching process should be used as much as possible.
(6) For precision and complex molds, vacuum quenching and cryogenic treatment after quenching should be used as far as possible.
(7) For some sophisticated molds, pre-heat treatment, aging heat treatment, quenching and tempering heat treatment can be used to control the precision of the mold.
(8) When repairing defects such as sand holes, pores, and wear of the mold, use a cold welding machine and other repair equipment with little heat influence to avoid deformation during the repair process.
There are many methods for heat treatment process operations, including, for example, plugging, tying holes, mechanical fixing, proper heating methods, accurate selection of the cooling direction of the mold, and the direction of movement in the cooling medium. Reasonable tempering heat treatment process is also an effective measure to reduce the deformation of sophisticated molds.
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