材料期刊网

针对质量异议批次的35CrMnSiA钢棒材生产液压支架销柱断裂异议,为找出断裂产生原因,采用金相显微镜,电子探针和光谱分析等宏观和微观方法对样品进行了系列分析,结果表明：材料成分、低倍、夹杂物和晶粒度符合GB/T3077-1999标准要求,探伤和组织均正常。断裂主要是由于销柱横向通孔内表面加工粗糙,淬火时尖锐处产生断裂源及随后扩展所致,并提出预防该缺陷措施。

Metallographic microscope, EPMA and spectrum analysis were applied to analyze the cracking of hydraulic support frame spin made of 35CrMnSi steel. The results show that the chemical composition, macro-etching mor- phology, nonmetallic inclusion rating and grain size of the cracking parts meet the requirements of GB/T 3077-- 1999. The ultrasonic testing and microstrcture observation indicate that the cracking parts are qualified. The micro- structure observation illustrate that the cracking was caused by the inner surface's poor smoothness of the through hole on the spin's cross-section. Micro-cracks initiate at the sharp areas of the rough inner surface during quenching process and propagate thereafter. Measures have been put forward to prevent the cracking.