U71Mn与U75V钢轨焊接过热敏感性对比分析

Comparative Analysis of Overheating Sensitivity of U71Mn and U75V Rail Welding

U71Mn钢轨和U75V钢轨在闪光对焊中表现出不同可焊性。为研究2种钢轨的可焊性,结合接头性能检验数据和焊接工艺参数,分析加热程度与各质量性能指标的关系。在不同加热程度下,U71Mn钢轨和U75V钢轨表现出不同焊接过热敏感性。U71Mn钢轨过热敏感性强,加热程度指数越高,落锤性能越差,灰斑越多。U75V钢轨焊接过热敏感性差,加热程度指数越高,落锤性能越强,灰斑越少。通过分析,得出U71Mn钢轨的加热程度指数合理值为不大于30,U75V钢轨的加热程度指数合理值为不小于35。

U71Mn and U75V rails show different weldability in flash butt welding. To study the weldability of these two types of rail,the article analyses the relationship between heating degree and each quality performance index by combining the joint performance inspection data and the welding parameters. Based on different heating degree,U71Mn and U75V show different welding overheating sensitivity. U71Mn rails is strong in overheating sensitivity. The higher the heating degree index is,the poorer the falling impact performance is and the more the greyness is. U75V rails is poor in overheating sensitivity. The higher the heating degree index is,the stronger the falling impact performance is and the less the greyness is. Based on the analysis,it is concluded that the rational heating degree index value for U71Mn rail is no more than 30,with that for U75V rail no less than 35.