材料期刊网

车轮常规检验中拉伸试样出现批量脆断情况。为确定车轮拉伸脆断产生的原因，进行了调查研究、拉伸比对试验和解剖检验分析。金相检验发现拉伸试样表面存在异常的马氏体白层。结果表明：加工过程控制不当导致试样表面产生马氏体白层，导致发生车轮拉伸试样脆断。

A batch of brittle fractures are found in routine tensile test for train wheel .In order to find out the reasons, investigations on tensile compare, dissection analysis and so on have been carried out. Metallographic examination shows that exceptional martensite exist in the surface layer of sample. So it can be concluded that during machining tensile sample unseemly operations leads to martensite in the surface layer and wheel’s brittle fracture.