U71Mn钢轨的焊接过热敏感性分析

Analysis of Welding Overheated Sensitivity of U71Mn Rail

针对实际生产过程中U71Mn钢轨焊接接头落锤及断口检验通过率偏低的问题,选取U71Mn和U75V钢轨,对比分析其焊接接头的落锤次数、冲击功、平均灰斑面积、抗拉强度、静弯值、伸长率6项主要指标与加热程度指数之间的关系。分析结果表明,U71Mn钢轨存在比较明显的焊接过热敏感性。避免钢轨的焊接过热敏感性对钢轨焊接质量的影响应从钢轨材质、焊接方法、焊接工艺等方面综合考虑。提出了焊接过热敏感性强的钢轨在焊接过程中应注意的问题。

Aiming at the low pass rates of drop hammer and fracture inspection of U71Mn rail welding joints in the actual production process,the rail of U71Mn and U75V were selected to compare and analyze the relationship between heating degree index and six major indexes of welding joint such as drop hammer number,impact work,average grey spot area,tensile strength,static bending value and elongation.The results show that the welding overheated sensitivity of U71Mn rail is obvious.The inf luence of overheated sensitivity on rail welding quality should be considered comprehensively from rail material,welding method and welding technique.The problems that should be paid attention to during welding of rail with strong overheated sensitivity were put forward.