Φ100mm三辊连轧管机组荒管“划伤”缺陷分析及对策

Investigation of Defective Scratch of Shell as Rolled with Φ100 mm 3-roll Mandrel Mill

针对Φ100mm三辊连轧管机组荒管外表面容易出现金属"划伤"缺陷的问题,在分析成因的基础上,通过重新分配穿孔与连轧工艺的变形量,优化连轧管机孔型,针对不同规格毛管设定各机架速度制度,更换磨损严重的机架下楔块等措施,有效地减少了"划伤"缺陷的产生。

Addressing the problem that scratch defects as made by metallic operation tool often occur on the outer surface of the shell as rolled with the Φ100 mm 3-roll mandrel mill,the causes are investigated,and then identified.Accordingly,a number of measures are taken,including re-distributing the deformation amounts of the workpiece in both the piercing process and the mandrel mill-rolling process,optimizing the passes of the mandrel mill,determining the rolling speed schedule of each stand of the mandrel mill as per the size variation of the shells,and replacing worn-out wedges beneath the roll-stand and so on.As a result,the occurrence frequency of the above mentioned tube scratch defect is obviously reduced.