PG4 75 kg·m-1热处理钢轨在焊轨厂的焊接工序前, 发现数支钢轨在轨底出现裂纹、掉块伤损。对伤损钢轨取样进行检验、分析, 发现钢轨的化学成分、力学性能、显微组织及非金属夹杂物级别均符合相应技术标准要求。根据钢轨裂纹伤损特征, 采用MSC·Marc软件对钢轨堆垛中的受力状态进行了仿真计算分析。结果表明: 钢轨出现轨底裂纹伤损的原因是, 钢轨堆垛时未按要求放平, 钢轨出现倾斜, 造成一侧轨底角局部受力过大, 从而产生裂纹伤损。

Before welding procedure for PG4 75 kg·m-1 on line heat treated steel rail, cracking and spalling damage were found on bottom surface of the steel rail. Specimens were sampled from the defective rails for test and analysis and it was found that all technical parameters such as chemical compositions, mechanical properties, microstructure and non-metallic inclusions met the requirements of relative standard. Based on characteristic of the bottom cracking damage, MSC·Marc software was used to simulate the stressed state when rails stacking. The results showed that when some rails were non-level stacked, excessive stress would apply on one side of the rail bottom, which resulted in the bottom cracking damage finally.