Experimental Study On Stretch Reducing Process Of Pipe And Finite Element Simulation Under Crop End Control

Approximately 50 million tons of steel tube and pipe products are consumed in the world annually. Development of the innovative tube processing technology has always been one of the key focuses in the steel industry in the world. Stretch reducing is the finishing step in hot rolling of seamless steel tube, due to the complex of metal flow during tube reducing process, it's difficult to control the process of metal flow in a precise fashion. In manufactory, roll profile and process parameters have to be decided by repetitive trials. As a result, it will lead to high production cost, long production cycle and hard to develop new products. In the initial period of tension-reducing machine putted into use, people discovered that the two ends of the pipe wall thickness greater than the central after tube rolling called end-of-pipe thickness. This is the inherent character of tension-reducing. If the end-of-pipe wall thickness is more than the finished product tolerance, excision must be done, so made the rate of units-receiving lower and economical decline. Accordingly to that, the steel tube manufactures are made multiple study in reducing the thickness of the end of tube, and achieved some results. Now, the method of controlling roll speed dynamics is used in the existing units known as crop end control.In this paper, an experiment is done on tube rolling mill, and establish finite element model in rolling process simulation based on rolling mill and tube parameters. The simulation results and experimental data fit close, and then proved the reliability of the finite element method.Secondly, the paper program CEC speed system software through VB. The software can calculate CEC time and response speed rapidly in different parameters input and also can provide users many output methods.Finally, it certified that the CEC speed system software is correct and practical, by compared constant speed rolling with variable speed rolling using the finite element method. Therefore, the study have great realistic significance in develop of reasonable rolling tension-reducing technology.