45钢高强度垫圈开裂原因分析

An Analysis of Crack Reason of High Strength Plain Washers

某厂生产的45钢高强度垫圈出现表面中心开裂现象,采用金相显微镜和电子探针等手段,分析其开裂原因。结果表明:试样中心存在偏析条带,偏析条带上富集有P、Si、Mn等元素,元素偏聚造成材料组织完整性被破坏,在淬火过程中应力大于材料本身强度,在较为薄弱的中心偏析带上发生开裂并扩展,最终造成零件失效。

45 steel high strength plain washers cracking occurred in the production process. The crack- ing reasons were analyzed by means of metallographic microscope and electron probe. The results show that the presence of segregation band with the elements enrichment of P, Si, Mn, and elements segregation in the center of the sample destructed the integrity of the material, and that in the quenching process, stress exceeds the material strength with the result that cracking occurred in the weak center and extend- ed, resulting in failure of plain washer.