兩種機型穿孔鋼管的內(nèi)螺旋產(chǎn)生原因及控制

Causes for and Eliminating of Inner Surface Spiral-line Marks of Steel Pipes as Made with Two Different Types of Piercing Mills

摘要: 兩種典型斜軋穿孔機型（桶形輥穿孔機和錐形輥穿孔機）熱穿軋的無縫鋼管，在軋制過程中容易產(chǎn)生內(nèi)螺旋缺陷。從變形區(qū)、軋制冷（熱）工具方面分析了穿孔毛管形成內(nèi)螺旋缺陷的原因。提出增加1個斜軋機架、減小軋輥出口錐的輥面角度、準確選擇軋制冷（熱）工具、防止外界因素干擾等減少鋼管內(nèi)螺旋缺陷的措施。

Abstract: It is commonly encountered with that defective inner spiral-line marks occur with seamless steel tubes being hot-rolled by either of the two typical piercing mills，i.e.，the barrel type rotary piercer and the cone type piercer.Causes for the said defect are investigated in terms of deformation zone and cold（thermal） rolling tools，and eventually identified.Accordingly，preventative measures are proposed，including adding one more cross-rolling stand，reducing the roll face angle of the roll outlet cone part，correctly selecting cold（thermal） rolling tolls，and preventing interference of any external element，etc.