30CrMo钢热穿轧毛管表面缺陷分析

通过宏观、扫描电镜、金相显微镜和光谱等方法对 30CrMo钢热穿轧毛管表面缺陷进行分析，结果表明，毛管表面缺陷是由于在轧管过程中轧管机组某轧辊表面粘异物或轧辊磨损严重，使轧辊表面形成凸块，轧制时压印在钢管外表面形成凹陷，随后续轧制毛管外表面的变形而延展成与轴向约成 30°角的螺旋、条状凹陷分布。

Analysis of surface defect hot piercing capillary of 30CrMo steel

The surface defects of the hot piercing capillary of 30CrMo steel were analyzed by means of macroscopical，scanning electron microscopy，metallographic microscopy and spectroscopy.The results showed that the surface defects of the capillary were caused by sticking foreign bodies on the surface of a certain roll or serious wear of the rollduring tube rolling，which resulted in the formation of bumps on the surface of the roll embossing on the surface of the steel pipe during rolling to for made pression.Then the defects on outer surface of the capillary was deformed and extended in to aspiral and strip depression with anangle of about 30 degrees to the axial direction.