Temper Rolling Process Analysis Of Invar Alloy Strip

Invar alloy is widely used as balance rocker arm,laser collimator cavity,instrument and other parts and materials because of its low coefficient of thermal expansion.In the actual production of some materials,it is found that the invar alloy strip will have a certain degree of side bending after slitting,which has a great impact on the subsequent coiling and application.The side bending of invar alloy strip after slitting indicates that there is a potential bad plate shape in the flat strip product.In the actual production,the roll gap shape has an important impact on the temper rolling of the strip,which is one of the main reasons for the bad shape of the strip.Therefore,the study of the roll gap shape and its influencing factors is the basis to further solve the problem.This paper mainly studies the temper process of invar alloy strip.Through the test and analysis of the basic mechanical properties of invar alloy strip and the finite element analysis of leveling rolling,the prediction of roll gap crown and the setting method of leveling process parameters of invar alloy leveling rolling roll are obtained,which provides a theoretical basis for further solving the problem of poor shape after invar alloy leveling.The main research contents include:(1)The 2D rigid roll flattening model is established to simulate the flattening and rolling process of strip.The reduction rate and extension of strip can be analyzed by constant flattening rolling force.When the elastic flattening of roll is not considered,the elongation is significantly higher than the normal level.Therefore,the 2D elastic roll leveling model is established,and it is concluded that the elastic deformation and tension of the roll have a great influence on the elongation.(2)It provides the basis for the simulation of the influence of the strip diameter and elongation on the rolling force and flatness.For 1155×1.5 mm invar alloy,the elongation increases by about 1.36% for every 1000 k N increase in rolling force.When the tension increases by 10 k N,the elongation increases by about 0.1%.For every 10 mm increase in width,the elongation decreases by about 0.05%.With the increase of roll diameter,the strip elongation decreases.Within the variation range of roll diameter,the variation range of strip elongation is only 0.4%.It provides a basis for further setting the temper process parameters.(3)A three-dimensional elastic-plastic finite element model is established for the flat rolling process,focusing on the influencing factors and laws of roll gap shape.The prediction of roll gap crown and the setting model of process parameters are obtained.For the incoming invar alloy strip,the width is 1155 mm,the thickness is1.5 mm and the convexity is 60 μm.The leveling process parameters are set according to the requirements of leveling elongation of 1.5%,3.0% and 4.5%.