Research On Optimization Of Pass System And Schedule Of Break-down Rolling Of Large H-beam

H-beam has been widely used in the constraction of national economy because of its excellent cross section characteristics and good mechanical properties.In recent years,H-beam has made great progress in our country.But for large H-beams that are required in large buildings,the aspect ratio is large and the forming is relatively difficult,so the development is slow.Therefore,it is of great significance to study the rolling process and deformation of large H-beam.In this paper,based on the actual production data,large-scale finite element software MSC.MARC is used to simulate the rolling processes of large H-beam with small H-beam blanks,rectangular billets and large H-beam blanks.Sizes of section after rolling,equivalent plastic strain distribution,"tongue" phenomenon and rolling stability are studied.By comparing the deformation of three kinds of rolling conditions,the current pass system and rolling schedule are improved for large H-beam during break-down rolling.The results show that the equivalent plastic strain distribution of billet is inhomogeneous,and the deformation of web and flange is not harmonious due to the restriction of billet sizes and pass system,when the small H-beam blank is used.The uneven deformation resulted in the "tongue" phenomenon at the web of billet.The maximum "tongue" length is 69.6 mm.The billet is prone to tilt because of the thinner web during erect rolling.When the rectangular billet is used,the larger equivalent plastic strain of each pass appears in the web or web and flange connection,and the equivalent plastic strain of flange is relatively small,and deformation of billet is not uniform.The largest tongue length of web is 162.3mm.When large H-beam blank is u sed,the equivalent plastic strain distribution of web and flange is relatively uniform,and the deformation of billet is consistent.The rolling force of each pass is more balanced,and the length of "tongue" in the web is less than other two kinds of rolling conditions.In addition,web of billet is relatively thicker after rolling,which can effectively improve the homogeneity of deformation during universal rolling.At the same time,the stability of the erect rolling is relatively better,which can avoid the slanting of the billet.The resultsobtained in the paper can be used to improve the pass system and schedule for large H-beam break-down rolling,and it can offer references for the selection of rolling pass system and product quality improvement.