28CrMo40钢管表面凹坑及结疤缺陷分析

Concave and scarring defect analysis on 28CrMo40 steel pipe surface

针对?130 mm的28Cr Mo40钢轧管后发现钢管表面有凹坑及结疤等缺陷,采用化学成分分析、金相组织检验及X射线能谱分析等手段,对28Cr Mo40钢管表面凹坑及结疤的产生原因进行了分析。分析结果表明:28Cr Mo40钢管表面结疤缺陷是由于轧辊或导向辊材料的剥落并压入钢管表面所致,同时轧制线上其他低碳类的金属异物也有压入钢管表面的现象;当压入的压嵌块状物脱落时则形成凹坑。并提出了防止类似缺陷产生的措施。

Concave and scarring defect were found on the steel pipe surface after the tube rolling of Ф130 mm 28CrMo40. An analysis was conducted on the reason behind the production of concave and scarring on 28CrMo40 steel pipe surface by using chemical component analysis, metallographicstructure examination and X-ray energy spectrum analysis. Results showed the scarring defect on 28CrMo40 steel pipe surface was caused by peeling off of the roller and guide roller materials and their pressing into the steel tube surface. Meanwhile, other low carbon metallic foreign body at the roller line also seemed to press into steel pipe surface. And the concave was formed after the peeling off of embedded block. In addition, counter measures were proposed to prevent such defects.