内燃机曲轴用42CrMoA钢表面压痕产生原因及质量改进

Causes of surface indentaion and quality improvement of 42CrMoA steel for internal combustion engine crankshaft

针对某批次内燃机曲轴用42CrMoA钢棒毛坯喷砂后其表面压痕明显的问题,采用宏观观察、化学成分分析、低倍检验、金相检验及扫描电镜分析等方法,对不同表面质量曲轴毛坯所对应的不同炉次42CrMoA钢棒进行了研究,并设计了改进试验方案。结果表明:曲轴表面压痕的产生与棒材原始表面粗糙度无关,而与棒材原始化学成分有关。适当地提高S,Al元素含量,并控制P,Ni,Cu元素含量可改善曲轴毛坯表面的压痕情况。

Aiming at the problem that the surface indentation of 42CrMoA steel bar blank used in a batch of internal combustion engine crankshaft was obvious after sandblasting,macroscopic observation,chemical composition analysis,macroscopic examination,metallographic examination and scanning electron microscope analysis were used to study the 42CrMoA steel bars corresponding to different surface quality crankshaft blanks,and the improved verification test scheme was designed.The results show that the generation of crankshaft surface indentation was not related to the original surface roughness of the bar,but related to the original chemical composition of the bar.Appropriately increasing the content of S and Al elements and controlling the content of P,Ni and Cu elements could improve the indentation of crankshaft blank surface.