The method of preheating deformation of straight seam steel pipe

The method of preheating deformation of straight seam steel pipe

1. Reasonable selection of materials. For precision and messy molds, micro-deformation mold steels with good materials should be selected, and mold steels with serious carbide segregation should be reasonably cast and quenched and tempered. Reasonable selection of heating temperature and control of heating speed. For precision and messy molds, slow heating, preheating and other balanced heating methods can be used to reduce heat treatment deformation of the mold.

2. Correct heat treatment process operation and reasonable tempering heat treatment process are also useful methods to reduce the deformation of precision and messy molds. The reasons for the deformation of precision and messy molds are often messy, but they can be reduced and controllable only by mastering the deformation rules, analyzing the reasons for its occurrence, and choosing abnormal methods to avoid the deformation of the mold.

3. Pre-heat treatment should be carried out for precision and messy molds to eliminate the remaining stress during machining. For precision and messy molds, vacuum heating and quenching and cryogenic treatment after quenching should be used as far as possible. On the premise of ensuring the hardness of the mold, try to use pre-cooling, graded cooling quenching, or a warm quenching process.

4. The design and description of the mold should be reasonable, the thickness should not be too disparate, and the shape should be symmetrical. For large deformation molds, the deformation rules should be mastered, and machining allowance should be reserved. For large, precise, and messy molds, a combined design can be used. For some precision and messy molds, pre-heat treatment, aging heat treatment, and quenching and tempering nitriding heat treatment can be used to control the accuracy of the mold. When repairing mold blisters, pores, wear and other defects, use equipment with small thermal effects such as cold welding machines to avoid deformation during the repair process.