借助于光学显微镜、扫描电镜, 对开裂的连杆精锻模具进行了断口分析、钢中非金属夹杂物检验、硬度测试、横截面低倍检验、裂纹源处以及距裂纹源处横截面上1/4, 1/2(心部)处显微组织的检验和分析。结果表明: 该模具材料中存在严重的微观组织偏析现象及明显的加工刀痕造成的应力集中, 是使该模具发生早期脆性断裂的主要原因, 并提出了改进措施。

By means of optical microscope and scanning electron microscope, the cracked mould for connecting rod forging was analyzed including fracture analysis, nonmetallic inclusion detection, hardness testing, macroscopic detection of cross section, metallographic examination of crack source and the position of 1/4, 1/2 (core) of cross section from crack source. The results showed that the main cause of early brittle fracture of mould was material segregation and stress concentration caused by serious tool marks. Meanwhile, the suggestions were put forward.