The influence of over-heat and draw speed on inner fold defects of seamless steel tube is analyzed in hot test process of 20 steel from point of view of inner solidified organization of CC billet.

• 从连铸坯内部凝固组织的角度出发,分析了20钢在热试过程中,过热度、拉速对无缝管内折缺陷的影响,并提出了改善内部组织的措施,以减少内折废品的产生。