Pass Design Of LG730 Cold-rolling Pilger Milland Its Finite Element Simulation In The Rolling-process

Two-high cold-rolling pilger mill is equipment for shell rolling in the cold-rolling process with a variable circular cross-section dies. Cold-rolling pilger mill is widely used in the modern metal pipe production, especially in the production of steel, nonferrous alloys and various alloy pipe of high deforming resistance. To meet with the domestic user’s needs and the specific requirements of the pipeline in nuclear power station industry in the future, it is necessary to develop a large two-high cold-rolling pilger mill. LG730 is the world’s largest two-high cold-rolling mill with servo controlling. It has a good breakdown performance, and can also roll the large diameter seamless pipe of ferrous metal and non-ferrous metal.In the cold-rolled pipe production industry, pass design is the key technology of the cold-rolling mill technology, which is to provide the most reasonable working tool for metal deformation. The rationality of roller-pass design has an important influence on the dimension accuracy, surface finish and deformation uniformity of the cold-rolled seamless steel pipe. Meanwhile, the rationality of roller-pass design can also affects axial force, mill productivity, production costs and rolling force distributions in deforming zone. Russia has the world’s largest two-high cold-rolling mill up to now, and the maximum outer diameter of its finished pipe is 450 mm. To meet with the needs of the larger diameter cold-rolled steel pipe with the limit size 730 mm in the nuclear industry, there are new problems to solve in the pass-design theory and production practice. The current theory of pass design is generally based on experience; we can hardly know whether the traditional pass design theory is suitable for the large-diameter. Large diameter cold rolling mill with the limit size of Φ730mm has never been produced around the world, so the pass design of LG730 cold rolling mill has no precedent in both theory and actual production. The main problem to be solved in this issue is to crack pass design of large diameter hole to build mathematical modelsFor this reason, to meet with user’s needs, Sheva roll pass design method and MEER roll pass design method are used for the roll pass design of LG730 cold-rolling mill, and finite element software MARC is used to establish a elastic-plastic finite element model to simulate the typical rolling schedule process of the world’s largest two-high servo-controlling cold-rolling mill LG730.This thesis mainly do some research in the ring-pass design, and develop software forpass design to establish the parameterized model. It has solved the problem of model setting for the reciprocating rolling movement and the elongation and feeding and turning movement, and has provided important simulation data during the design process of LG730 cold-rolling mill, finally carry out the conclusion of the accuracy of MEER pass design theory. This research will play an important role in the large diameter seamless steel cold-rolled pipe industrial production, and will also have a considerable influence on the development and technological advances of the cold-rolled seamless steel pipe industry. It will truly have a great value for theory refining and practical use.