管坯缩径穿孔的实践

Practice of O.D.-reduction Piercing Process

介绍了3种不同形式的管坯穿孔工序,通过对桶形辊和锥形辊不同辊形穿孔机的管坯缩径穿孔工艺的实例剖析,运用理论知识分析了生产中所出现的问题并找出了相应的解决办法。实践证明,使用管坯缩径穿孔的基本条件是变形区前移;在桶形辊穿孔机上实施管坯缩径穿孔比在锥形辊穿孔机上容易。采用管坯缩径穿孔的工具消耗以及轧机负荷比扩径穿孔要高。

Three different piercing processes are described. With case analyses, the O.D.-reduction piercing processes with barrel roll piercer or cone type piercer are investigated. Based on relevant theories, problems concerning the piercing operations are analyzed, and countermeasures are determined. The operation practice shows that the precondition for O.D.-reduction piercing operation is forward-shifting of the deformation zone, and that O.D.-reduction piercing with barrel roll mill is easier than that with cone type mill, and that the tool consumption and mill load for O.D.-reduction piercing is higher than those for O.D.-expansion piercing.