【摘要】 针对U71Mn钢轨闪光焊探伤超使用标准的现象进行试验研究。分析接头形貌和缺陷特点,发现大部分缺陷位于熔合线附近,以孔洞及裂纹形式存在。在少量孔洞表面及裂纹尖端存在硫化物。这些孔洞缺陷是由于焊接参数匹配不良而产生过烧,使低熔点偏析晶界熔化并拉开所造成的。通过调节焊接参数,消除了过烧现象,保证了接头超声波探伤合格。更多还原

【Abstract】 Butt flash welding experiment is carried out to solve the UT failure problem of U71 Mn steel rail. The appearance of welded joint and the characteristics of defects are analyzed. Most defects lie near the fusion line mainly in the forms of holes and cracks,and sulfides are found on a few hole surfaces and crack tips. These hole defects are caused by the overburning produced by improper welding parameter matching. The overturning makes the low-melting-point segregation grain boundary melted and separated. By adjusting welding parameters, the overburning is eliminated and the UT qualification of joints is ensured.更多还原