我厂一台新的三吨模锻锤的下模座,使用不到两年就因产生大开裂而报废,这种情况是少见的。我们对损坏的模座做了硬度检验及金相化学成分分析,结果均属正常。对开裂部位进行了详细检查,发现下模座正面(A)左边的定位键槽的 ab 边转角处有一条大裂纹,已上下裂通(如图1所示),b 边上有七八条小 It is not uncommon for the lower die holder of a new three-ton die forging hammer in our factory to be scrapped in less than two years due to cracking. We do damage to the mold base hardness test and metallographic chemical composition analysis, the results are normal. The cracking site was examined in detail and found that there was a big crack in the ab corner of the positioning keyway on the left side of the lower mold base (A), which had been split up and down (as shown in FIG. 1), and there were 78 small