Study On Four-roller Roll Forming Process Of Bimetal Cladded Plates

Titanium-steel cladded plates which have both the corrosion resistance of titanium and the toughness of steel are widely used in various cylindrical parts such as various chemical reaction vessels,heat exchanger materials,power plant desulfurization chimneys and so on.Due to the difference in metal properties of the titanium and steel,the deformation mechanism and deformation law of the cladded plates are not yet clear.In order to obtain the required cylinder diameter,it is necessary to continuously adjust the feeding amount of upper roller and side rollers according to the spring-back and sample size inspection results during the rolling process,which severely limits the processing efficiency and rolling accuracy.The paper focuses on the roll forming process of titanium and steel clad plates on the side-roller linear four-roller rolling machine,aiming to reveal the bending deformation mechanism,develop the basic theoretical model of the titanium and steel clad plates roll bending process in the four-roller bending machine,and improve the efficiency and accuracy of the titanium steel clad plate roll bending to meet the increasing demand for coil accuracy in chemical industry,pressure vessel,seawater desalination,etc.Based on the finite element analysis software Marc,a finite element analysis model of the titanium steel clad plates roll forming process with the side-roller linear four-roller plate rolling machine was established.And the field variables such as equivalent plastic strain,equivalent stress,and equivalent elastic strain in the clad plate during roll bending were analyzed.The change law and the deviation law of the neutral layer in the stable winding stage,and the force change of the side roller during the whole roll bending process were revealed.The effects of the component thickness ratio of the titanium steel clad plate,different thicknesses,the distance between the rollers on both sides,and the feed of the side rollers on the roll bending of the titanium steel clad plate were analyzed.The radius of the cylinder is greatly affected by various parameters.The offset of the neutral layer increases with the thickness of the composite plate,and it increases first and then decreases with the increase of the layer thickness ratio.Based on the existing four-roller roll forming theory of single materials,the process model of single metal roll bending is improved by introducing the offset of the neutral layer and reducing the iterative calculation variables.Combined with the existing bilayer composite plate neutral layer offset theory,the neutral layer offset under the material bilinear hardening model is analyzed,and the bending stiffness of the bimetal composite plate is introduced to establish the bimetal composite plate roll bending process The analytical model of the typical titanium steel composite plate roll bending process was verify by finite element analysis.