Thick-walled Tube Diameter Process Simulation And Experimental Study Of The Inner Wall Of The Straight Side Tension Reduction

Seamless steel tube is widely used in the national economy, the tensionreducing process is an important link of seamless steel tube production. Aftertension reducing process, tube often produce defect of wall straight side (hexagonpolygon),Especially the thick wall tube. It reduces the size precision of steel tube.With the continuous development of steel tube production technology andinnovation, how to improve this kind of defect is always a difficult problem, toimprove our country’s steel production capacity has very important significance.This article first introduces process of steel tube production and the tensionreducing, and the research status, then raises the objective of this article. It studiesthe process parameter which affect the hexagon polygon of thick wall tube. Usefinite element software ANSYS/LS-DYNA simulate the thick wall tube tensionreducing process with thermal coupling numerical simulation, through analysis ofstress and strain distribution and temperature distribution of steel tube, wallthickness distribution and rolling force distribution in tension reducing. Thiswork gives a good base for later research of the hexagon polygon.Then studies the influence of reducing rate to the hexagon polygon, byincrease or decrease stands number to achieve the increase and decrease of thereducing rate, simulates the different groups of reducing rate for the tensionreducing process, the results shows that increasing reducing rate can effectivelyimprove the hexagon polygon phenomenon. Study the influence of tensioncoefficient to the hexagon polygon, by applying different tension coefficient tochange the size of the tension, simulates the different groups of tension coefficientfor the tension reducing process, the results shows that increased tensioncoefficient within a certain range can effectively improve the hexagon polygon, ifthe tension coefficient is too large, the effect to improve the hexagon polygon isnot obvious. Through the analysis of the tube hexagonal polygon phenomenon,proposed skew stretch reducing process which deflect the roller centerline with aangle, So tube get a spiral motion in the stands. Simulate the process of skew stretch reducing and longitudinal stretch reducing, comparing the degree ofhexagonal polygon between two reducing rolling process indicated that the skewstretch reducing could improve defects of the hexagon polygon effectively.Verifies the influence of tension coefficient to the hexagon polygon with thethree-roll experimental rolling mill of Taiyuan university of science andtechnology. The experimental results consistent with the trend of simulation study.In this article, three kinds of optimization measures can effectively improve thehexagon polygon defects, and also provides a new optimization ideas to thetension reducing process design, has certain guiding significance for thesubsequent research.