Design Of The Core For ?650 Short-Stress-Path Bar Rolling Mill

Metal bar production and its growth keep in a high level in China,regardless the quantity of bar mills or bar production rank first in the world.However,the installed level of bar rolling mills is rather spotty.There are still many equipments with high pollution and high energy consumption under production should be eliminated,meanwhile domestic metal companies are unable to produce high quality and high value-added metal bar materials of certain grades.Some special steels and bearing steels are still imported or made by forging.The bar rolling mills designed and manufactured in China are generally for bars below ?250mm,mills for ?250mm or above are normally imported.The short-stress-path rolling mills that composes one part of the largest bar production line in China,produce bar diameters up to ?360 mm,is imported from Pomini(Italy).This paper associates with the R&D of large bar rolling mills in the author's company,aims to develop a prototype of a ?650 short-stress-path mill for bar diameter up to ?250 mm and promote domestic manufacture of large bar rolling mills.In this paper,the author mainly focuses on the design of the core structure of this mill.The main contents are as the following:First,Market analysis of short-stress-path rolling mills.Through the research on China's steel production and bar production lines,and the analysis of the history of short-stress-path rolling mills,the ?650-type has been set as the research object.Second,Schematic design of the core structure of short-stress-path rolling mill.Research of the rollers,tie rod,roller bearings,upper roller balance device and axial locking device,rolling gap adjusting device in the roller system has been carried out,and solutions to some unreasonable aspects of conventional structure are proposed.Third,Study of the roll process of the short-stress-path rolling mill.The layout of bar forming hole has been analyzed.The roll process has been set up based on the production flow.The life of rollers and bearings of short stress path rolling mill has been enhanced.Forth,FEM analysis of the core structure of the short-stress-path rolling mill.The working condition of the ?650 rolling mill has been simulated by FEM to calculate accurate deformation,through which the gaps of related parts are determined.