大直径不锈钢管内旋压成形的金属流动堆积缺陷研究

Study on Metal Flow Accumulation Defect as Occurring with Large-sized Stainless Steel Tube during Internal Spinning Formation Process

采用Abaqus软件仿真分析大直径不锈钢管在内旋压成形过程中的金属流动堆积现象。采用单因素控制法讨论了壁厚分别为20 mm、12 mm和7 mm时Ф508 mm不锈钢管在三旋轮内旋压过程中的等效应变、金属流动及旋轧力的变化规律,并分析了不同厚度时层间金属质点的流动速度,进一步得出金属流动堆积的原因。结果表明:随着初始壁厚值的不断减小,壁厚为7 mm时,旋轮前方产生的金属堆积高度达到9 mm,接触区的等效应变值最大达到7.9,产生的旋轧力高达450 kN。可见,在相同工况下,钢管的壁厚越小,接触区的等效应变值越大,所需旋压力也越大,产生的金属堆积现象越严重。

The Abaqus finite element software is used to simulate and analyze the metal flow buildup phenomenon of the large sized stainless steel pipe as occurring during the process of internal spinning formation process.Using the singlefactor control method,discussions are made on the change regularities of the equivalent strain,the metal flow and the rolling force of the Ф508 mm stainless steel tube during the 3-wheel internal spinning process under the conditions that the tube’s wall thickness is 20 mm,12 mm and 7 mm respectively.And flowing velocity of the interlayer metal particles in case of different wall thickness of the tube is analyzed,and thus the reason for the metal flow accumulation is identified.As a result,it is revealed that along with the continuous reduction of the initial wall thickness value,in case of 7 mm wall thickness,the metal accumulation as formed in front of the spinning wheel is high up to 9 mm,while the equivalent strain value of the contact area reaches the maximum value of 7.9,and spinning rolling force is up to 450 kN.Therefore it is obvious that under the same working conditions,the lighter the wall thickness,the bigger the equivalent strain value of the contact area,and the bigger the spinning force as needed,which leads to the more serious metal buildup phenomenon.