12Mn输油管线无缝钢管表面微裂纹成因分析

Analysis on the Causes of Surface Microcracks in 12Mn Seamless Steel Tubes

12Mn无缝钢管在调质处理过程中,钢管表面出现微裂纹。采用光学显微镜、扫描电镜和能谱仪、光谱仪等设备对该裂纹的宏观特征、形成原因进行了系统的分析研究。结果表明,该种缺陷的形成是由于铸坯表面存在微裂纹所致。通过采取一些有效的工艺技术措施,铸坯表面的微裂纹基本消除,钢管表面的微裂纹随之减少甚至消除,提高了产品质量,降低了生产成本。

In the process of quenching and tempering of 12Mn seamless steel tubes, the microcracks were appeared on the surface of the steel tubes. The macroscopic characteristics and formation reasons of the cracks were systematically analyzed using optical microscopes, scanning electron microscopes, energy spectrometers, and spectrographs. The analysis results show that the formation of this kind of defect is caused by the micro-cracks generated on the surface of the slab. By adopting some effective technological measures, the micro-cracks on the surface of the billet can be substantially eliminated, thereby eliminating the micro-cracks on the surface of the steel tube. This has improved the product quality and reduced the production costs.