Abstract: With decreasing the outside diameter of 0. 45C steel tube before 6 stands reducing and the total reducing rate respectively from 132 mm and 12. 95% to 128 mm and 9. 87% , decreasing single stand reducing rate and improving roll pass design parameters for faint tension reducing, the hexagonal bore index P value of Φ114 mm x 22 mm 0. 45C steel tube produced by three roll mill decreases to 0. 45% - 0. 67% from original 1.40% 〜1.52% , therefore the deformity of hexagonal bore of faint tension-stretched reducing steel tube is obviously decreasing.

Key words: Stretch Reducing Mil] with Faint Tension, Hexagonal Bore, Reducing Rate, Roll Pass Design Parameters

摘要： 通过将6机架定径前45钢管外径和总减径率分别由132 mm和12.95%降至128 mm和9.87%,并降低单机架减径率和改善微张力减径孔型设计参数,使3辊式机组生产的Φ114 mm×22 mm 45钢管"内六方"缺陷指数P值由1.40%～1.52%降至0.45%～0.67%,明显减少微张力减径钢管的"内六方"缺陷。

关键词: 微张力减径机, 内六方, 减径率, 孔型设计参数