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The influence of the geometry of precision molds on the deformation during heat treatment is actually still exerted through thermal stress and organizational stress. Due to the diverse shapes of precision molds, it is still very difficult to summarize the exact deformation rules from them at present.

For symmetrical precision molds, the deformation tendency of the cavity can be considered based on the cavity size, external dimensions and height. When the wall of a precision mold is thin and its height is small, it is easier to be quenched through. At this time, it is possible that the organizational stress plays a dominant role, so the cavity often tends to expand. Conversely, if the wall thickness and height are large, it is not easy to quench through. At this time, thermal stress may play a dominant role, so the cavity often tends to shrink. What is mentioned here is the general trend. In production practice, it is also necessary to take into account the specific shape of the parts, the type of steel used and the heat treatment process, etc., and continuously summarize experience through practice. In actual production, the external dimensions of precision molds are often not the main working dimensions, and after deformation, they can be corrected through grinding processing, etc. Therefore, the above analysis mainly focuses on the deformation trend of the cavity.

The deformation of asymmetrical precision molds is also the result of the combined effect of thermal stress and organizational stress. For instance, for precision molds with thin walls and edges, due to the thin mold walls, the temperature difference between the inside and outside during quenching is small, and thus the thermal stress is also small. However, it is prone to quenching through and has relatively high organizational stress, so the deformation tends to be cavity expansion.

To reduce the deformation of precision molds, the heat treatment department should work together with the precision mold design department to study and improve the design of precision molds, such as avoiding the structure of precision molds with significant differences in cross-sectional sizes as much as possible, striving for symmetrical shapes of precision molds, and using assembly structures for complex precision molds, etc.

When the shape of the precision mold cannot be changed, some other measures can also be taken to reduce deformation. The overall consideration of these measures is to improve the cooling conditions so that all parts can be cooled evenly. In addition, various coercive measures can also be supplemented to limit the quenching deformation of parts. For instance, adding process holes is a measure to ensure uniform cooling of all parts. That is, holes are made in certain parts of the precision mold to allow all parts of the precision mold to cool evenly and reduce deformation. Asbestos can also be wrapped around the periphery of precision molds that tend to expand after quenching to increase the cooling difference between the inner hole and the outer layer, causing the cavity to contract. Leaving or adding ribs on precision molds is another forced measure to reduce deformation. It is particularly suitable for concave molds with expanded cavities and precision molds with slots that are prone to expansion or contraction.