Simulation Of Forming Techniques Of Big Square Tube With Rollers

The use of big-diameter square or rectangle steel tube is extremely wide and most common section steel tube , it is a kind of economic terminal surface tube. Comparing with other non- round steel tubes , It have several merits such as light, the high intensity, the high flexural rigidity, saving the material, easy installation etc.It is also used widely in building , medical equipment , top-grade furniture , automobile , plane , subway , ship-building ,etc. The forming technology of big-diameter square or rectangle steel tube is dividing into the cold curved welded square tube and the seamless steel square tube, and the cold curved welded square tube is mainly in China. The welded square tube has two kinds of way to produce mainly. One kind is welded into round first, then finalize the design through a group of finalizing rolls. Another kind is bended the square first ,then welded. This paper mainly studies the course which become square from round, the structure of the mould adopt four rollers, it is suitable for the technology of taking shape the seamless steel tube or the round welded tube. Adopt four rollers ,The forming process of the square rectangle of big-diameter square or rectangle steel tube have a small metal-shape-speed and a symmetrical shape, a easy method of changing specification of tube by adjust center distance of rolls, its tube quality is also better such as the good straight degree, the long-lived tools and small energy consumption, So the technology especially widely used in forming of the small-diameter and thin tube .So ,In this paper ,I try to adopt four rollers to form the big-diameter and thick-wall square steel tube , but the big-diameter and thick-wall forming have its large deformation and the high resist strength , very easy to cause some flaws like the big roughness and destabilizing sector. In order to prevent the formulation of this kind of defect , it must find out about its variable force and stress inside, and control the forming shape of the pipe through adjusting the technological parameter in order to reach the instructions for use.This subject mainly make following work. At first ,it set up two kinds of finite element models use four roller in one pass and four passes. Secondly, it emulated and analyzed difference among the cold-drawing, cold-extruding and cold-rolling , and analyzed the law of variable stress ,variable strain and roughness in detail of the typical operating mode under the cold-drawing technology , Thirdly it adopt orthogonal experiments to analyze the effect of main parameter in one pass under the cold-drawing technology . Finally it take typical operating mode as an example, optimize the rule of the reduction in four passes under the cold-drawing technology.