编辑同志: 我厂规定:胎模在使用前必须预热至300℃左右。实践表明,这条规定是正确的。没有经过预热或预热不好的胎模,使用中都容易打裂。但是,规定的预热温度恰恰是处在一般钢的兰脆区,这时模具反而不易打裂,不知是何道理?望给解释一下。贵阳某厂读者贵阳某厂读者: 模具打裂的原因是较复杂的,影响因素颇多,由于对您厂的模具材料、热处理工艺和使用情况不了解,很难具体地分析原因,以下只能谈一下一般的看法。模具预热的作用,主要是消除或降低模具的残余应力,减少锻造时模具与锻件的温度差,因而减小了温度应力,同时由于模具预热减少了对锻件的冷却作用,因而有利于锻件的 Edit comrades: Our factory provides: mold before use must be preheated to about 300 ℃. Practice shows that this provision is correct. Without preheating or preheating bad mold, easy to use in the split. However, the provisions of the preheating temperature is precisely in the general steel blue crisp area, then the mold but not easy to crack, I do not know what reason? Hope to explain. Readers of a factory in Guiyang Readers of a factory in Guiyang: Reasons for mold splinters are more complex and have a large number of influencing factors. It is difficult to analyze the reasons in detail because of the lack of understanding of mold materials, heat treatment processes and usage of your factory. Talk about the general view. The role of mold preheating, mainly to eliminate or reduce the residual stress of the mold to reduce the forging die and forging temperature difference, thus reducing the temperature stress, while reducing the mold preheating forging cooling effect, which is conducive to forging of