Rolling Optimization In The Second Bar Factory Of Xiang Steel

This thesis is based on the Xiangtan Iron and Steel Company the Second Bar factory production actuality, Second Bar factory changed production construction for the changed market demand, they should change from small and middle size carbon round steel to large size low-alloyed steel tube stock. As the size of planchet increased, the original pass system does not suit for producing big bar product, so we optimized the pass system ofΦ800 blooming mill, and improve the finished pass system. Because the type of steel changed, we carried out the thermal simulation experiments in the THERMECMASTOR-Z thermal simulation machine with 20CrMnTiH and 40CrA, and analyzed the experiment results, obtained 20CrMnTiH and the 40CrA flow stress models, then used this model to collate the present rolling physical parameters of optimized pass system, then check rolling force, rolling moment and the motor power.Based on situation research,we obtained the following main research conclusions:1. Through the multi-dimensional non-linear return for stress-strain curve data, we obtained the flow stress mathematical models of 20CrMnTiH and 40CrA. These models are of simple structure and high precision in calculation and can be used in practical production.2. The two set of blooming pass system are able to meet the change of size and type of steel. Check rolling force, rolling moment and the motor power with this model, discovered the old rolling mill still could satisfy the new type of steels'production.3. Designed force down rules and match rollers for large size production, arranged pass reasonably, reinforced pass joint use, we reduce the blooming pass system designed by Italy from four sets to two sets, reduced the cost and increased the efficiency of rolling machine.4. Optimized the speed rules for theΦ800 blooming rolling mill, cut down the rolling time, and matched to the continuous rolling speed.5. We carried out the hot continuous rolling experiment to obtain appropriate broadside, then succeeded in designingΦ75~Φ90 round steel ellipse pass before finished pass andΦ140,Φ150 round tube stock finished pass, solve the overfill problem in the old pass system.