摘要
分别对贝氏体和珠光体钢轨闪光焊接头进行脉冲疲劳试验,发现造成贝氏体和珠光体闪光焊接头疲劳断裂的主要原因是焊缝存在的非金属夹杂物(即闪光焊灰斑缺陷);贝氏体钢轨闪光焊接头疲劳强度略高于珠光体;贝氏体钢轨闪光焊过热区存在的奥氏体晶界合金成分偏析或液化裂纹对疲劳强度的影响很小,目前未发现由此缺陷生成的裂纹源;贝氏体钢轨母材的成分偏析和珠光体钢轨闪光焊过热区MnS夹杂物对接头疲劳强度也有一定影响。
The pulse fatigue test was carried out for the flash butt welded joint of bainite and pearlite rail respectively.The experimental results showed that the main reason for the fatigue fracture of bainite and pearlite flash butt welded joints was the non-metallic inclusions( That was flash butt welding spot defects). The fatigue strength of the bainite rail flash butt welded joint was slightly higher than that of pearlite. The segregation and liquefaction cracking of the austenite grain boundary alloy in the flash butt welding of the bainite rails had little effect on the fatigue strength of the welded joint, and no crack source generated by such defects was found at present. The chemical composition segregation of the bainite rails and the Mn S inclusions in the superheated zone of the pearlite rail flash butt welding also had some effect of the fatigue strength of the welded joint.
出处
《焊接技术》
2017年第12期33-36,共4页
Welding Technology
基金
中国铁路总公司科技研究开发计划重点课题(2015G004-B)
(2016G005-E)
关键词
贝氏体钢轨
珠光体钢轨
闪光焊
疲劳性能
bainitic rail
pearlite rail
flash butt welding
fatigue properties
