摘要
针对生产中U71Mn钢轨气压焊接头断裂问题,利用扫描电镜、能谱仪及光学显微镜对接头的断口形貌、微观成分与显微组织进行了系统分析。结果表明:钢轨底面的锈蚀坑与磷元素的过度偏聚导致了裂纹萌生,并迅速扩展、断裂;轨头中间、轨底中间部位及轨腰部位同为脆性断裂,磷元素的局部偏聚是产生脆性断裂的主要原因,另外网状铁素体组织出现也明显降低了钢的强度、塑性和韧性。
Aiming at the breakage problems of gas pressure welded joint of Rail U71Mn steel, the morphology, composition and microstructure of the fracture surface were analyzed by scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and optical microscope （OM）. The results show that the excessive segregation of phosphorus and corrosion pits on the bottom surface of the rail result in the crack initiation, growth and fracture, and the brittle fracture occurs in the rail head, rail web and rail foot, which result from the local segregation of phosphorus. Furthermore, the ferrite net can obviously decrease the strength, plasticity and toughness of the rail joint.
出处
《热加工工艺》
CSCD
北大核心
2013年第19期215-217,220,共4页
Hot Working Technology
基金
淮海工学院自然科学研究项目(2010150001)
江苏省海洋资源开发研究院科技开放基金项目(JSIMR11B10)
关键词
钢轨接头
气压焊
断裂失效
rail joint
gas pressure welding
fracture failure
