φ76mm自动轧管机的孔型改进

MODIFICATION OF GROOVE OF φ76mm PLUG PIPE MILL

重庆钢铁集团钢管有限责任公司的φ76mm自动轧管机，以往采用传统孔型轧管，轧制的荒管有较多的耳子、鼓包、冒线和内楞子等缺陷；改进孔型后，即使使用刚换的新孔型，轧管也很顺利，二次咬入条件大大改善，所轧荒管缺陷减少，取得了较好的使用效果。

With the traditional grooves, the φ76mm plug pipe mill at the facility of Steel Tube Co. Ltd., Chongqing I & S Group previously produced tubes with such defects as fin,bulging, linear rolling mark and interior ridge. After modifying the grooves, even in case of a newly changed groove, the rolling operation is very smooth, and the secondary bite conditions have been improved considerably. Tubes rolled by the mill plant have had much fewer defects. It has been proven that the said modification has resulted in good performance of the mill.