Initial Thickness Ratio Design And Research On Hot Rolling Forming Of 316L/EH40 Clad Plate

Stainless steel clad plate is a kind of stainless steel and low alloy steel with different physical,chemical and mechanical properties by using composite technology,which is a multilayered composite produced by metallurgical bonding combined with heat and strength.Because of the great difference between the mechanical properties and the plastic deformation properties of the base and the cladding,the thickness and reduction of each layer of metal in the process of hot rolling are more complicated.Therefore,we need to establish the initial layer thickness ratio to control the thickness accuracy of each component of the clad plate,and then get the target layer thickness ratio of the clad plate.In order to control the thickness accuracy of 316L/EH40 clad plate in this article,the mechanism of hot rolling forming of clad plate is studied in depth by means of theoretical analysis,numerical simulation and experimental verification.The mathematical model of the rolling force of the stainless steel clad plate in the rolling deformation zone was established based on the slab method,and the calculation formulas of the rolling force and rolling moment were deduced accurately.The relative positions of the joints and neutral points in the rolling zone and various stress distributions were analyzed under different rolling process parameters.The correctness of rolling force model was verified by comparing the theoretical value with the simulation value.Based on the finite element software MSC.Marc,the single pass rolling simulation of clad plate was carried out,which studied stress-strain distribution along the thickness direction under the condition of different thickness ratio.The five pass reversible rolling simulation of clad plate was carried out,which obtained temperature,stress and strain distribution along thickness,and the residual stress and the rolling force distribution at the hot rolling interface were studied.The theoretical basis was provided for the prediction of mechanical properties and the optimization of process parameters in the process of subsequent hot rolling.According to geometry method,the initial thickness ratio was deduced.And the simulation of hot rolling forming was carried out based on the numerical simulation technology,and change law of thickness ratio was studied under the conditions of different rolling reduction and initial thickness ratio.It determined relationship between the reduction rate and deformation of various layers to the thickness ratio before and after hot rolling.The method of combining numerical simulation with theoretical calculation was used to determine the thickness matching formula of various layers of clad plate before hot rolling.It verified the reliability of the method model.Based on hot compression test machine of the Gleeble-3800,the compressive samples were obtained under the condition of different compression process of ship steel plate EH40,which analyzed deformation behavior of ship steel plate EH40 under high temperature,and the flow stress relationship of EH40 steel was deduced.The hot compression test of clad plate was carried out,and the thickness of base and cladding layer at each location was measured by ultrasonic thickness gauge.The influence of different process parameters on the thickness ratio was analyzed,and the accuracy of initial thickness matching of various components was verified.