大直径无缝钢管反挤压冲孔和顶管拔伸+斜轧组合生产工艺的研究及实践

反挤压冲孔和顶管拔伸+斜轧生产工艺组合灵活,适用于生产大直径,特厚、薄壁,高附加值特种无缝钢管,其成品几何尺寸精度高,表面质量好。该组合工艺与单纯斜轧和大顶管生产工艺相比有一定进步。采用大直径斜轧穿孔、均整、定径新工艺技术生产可部分替代现有的连轧+旋扩的生产工艺,属大直径薄壁无缝钢管生产领域的一种新实践。

Research and Application of Process Combining Backwardextrusion Piercing with Push Bench Drawing+Cross-rolling for Manufacture of Large-sized Seamless Steel Tubes

The combined process involving backward-extrusion piercing and push bench drawing plus crossrolling is flexible,and so suitable for manufacturing high value-added special seamless steel tubes like the large-sized,extra-heavy walled or light-walled ones featuring tight dimensional tolerances and fine surface quality.Compared with the conventional cross-rolling process or the extrusion process,the combined process is rather advanced.This process partially substitutes the new techniques such as cross-rolling/piercing,reeling and sizing of large-sized workpieces for the mandrel mill rolling＋rotary expanding process,being a pilot practice in the field of manufacture of large-sized,light wall seamless steel tubes.