The Technological Theory And Numerical Simulation Analysis On Cross Roll Straightening Process Of The Heavy Calibre Steel Tube

With the rapid development of national economy, the demands of heavy calibresteel tube increased constantly at home and abroad. As the last process of finishingproduction, the straightening process, to some extent, determined the final quality offinished steel tube. Therefore, taking the heavy caliber steel tube as study object, witha ten cross rollers straightening machine of a domestic enterprise as the base, a seriesof researches on the technological theory and numerical simulation of cross rollstraightening process of heavy calibre steel tube were carried out in this paper.Firstly, comparing the present design theories of cross roll straightening rollershape, considering the particularity of heavy calibre steel tube, a set of design theoriesapplying to heavy calibre steel tube were determined, including the straightening rollerdesign, the setting of straightening process parameters(the intermesh, flattening rateand inclined angle etc.), as well as the computation model of straightening force forthe calculations of mechanical parameters.Secondly, to the FEA software, MSC.MARC, as a platform, the ten cross rollersstraightening model of heavy caliber steel tube was established. The steel pipe model,Φ750mm×37mm, with the original cross-sectional ovality and longitudinal bendingdefects, was made to simulate dynamically the cold-straightening process at normaltemperature. The straightening effect on both ovality and bending defects,straightening stress and strain, as well as straightening force during the process, wereanalysed.In addition, in order to improve the production logistics and efficiency,and tomake full use of heat after rolling for energy saving, a new straightening solution,warm-straightening, was presented. A ten cross rollers warm-straightening model ofheavy calibre steel tube was also established, corresponding to the cold-straighteningprocess. Comparing the simulation results, the feasibility of warm-straightening was discussed, which provided a theoretical foundation for the process improvement inpractical production.In the end, using the programming language, Visual Basic, the integratedsimulation software on the cross roll straightening process of heavy calibre steel tubewas developed to meet the engineering application.