无缝钢管斜轧穿孔中环状内折产生原因探讨

Discussion on the Cause of Annular Internal Overlap on Seamless Steel Pipe Generated in Cone-roll Piercing

斜轧生产φ177.8 mm×9.19 mm BG100套管产品的过程中出现了异于常规螺旋内折的环状内折缺陷,对产品质量造成了严重影响。通过宏观和微观检验对环状内折的产生原因进行了分析。结果表明:管坯芯部区域存在的近似环向分布的氧化物夹渣及其次生的二次氧化物是造成环状内折缺陷的主要原因。

Annular internal overlap, which is different from regular helical internal overlap, was generated in the production of φ177.8 mm× 9. 19 mm BG100 casing pipe, and led to seriously influence to the product quality. By means of macroscopic and microscopic examinatin, the cause of annular internal overlap was analyzed. The results showed that the oxide slag and its secondary oxide which nearly circumferential distributed in the billet core were the main reason which caused the annular internal overlap.