Determination Of Process Parameters For Three-roll Planetary Rolling Of Silver Bright Stainless Steel Containing Bismuth

Bismuth-containing stainless steel not only has good cutting performance,but also bismuth and its oxides are clean and nontoxic,which is very suitable for stainless steel in food and medical industry.In the process of rolling bismuth-containing stainless steel bars by three-high planetary rolling mill,the core damage and surface spiral marks are serious due to unreasonable technological parameters.Therefore,the research on the core damage and surface spiral marks of bismuth stainless steel during rolling has important theoretical significance for the progress of the forming technology of bismuth stainless steel and the perfection of the technological parameters of three-roll planetary rolling.This paper takes three-roll planetary rolling of bismuth stainless steel as the research object.Through numerical simulation and theoretical analysis of the rolling process,the forming mechanism,core damage and surface quality of bismuth stainless steel are studied.The main research contents and conclusions are as follows:(1)The finite element model of three-roll planetary rolling is built based on ABAQUS software.Then,considering the influence of different process parameters on the core crack,25 groups of simulation experiments are carried out by orthogonal experiment.The maximum damage value of each experiment is calculated by variance analysis,and the optimal process parameters without core crack are selected.(2)Finite element simulation scheme is made according to the three factors that affect the surface spiral marks: deflection Angle,inclination Angle and section shrinkage.The time,position and cause of surface spiral marks in rolling process are analyzed,and the influence of three process parameters on surface spiral marks is explained.(3)By adjusting the process parameters and combining with the effects on the core cracks and surface spiral marks,the results show that when the rolling temperature is 1200?,the deflection Angle is 8°,the friction coefficient is 0.4,the inclination Angle is 50°,the roll speed is 120r/min,and the section shrinkage is 60.21%,there is no crack in the core and no spiral marks on the surface of the rolled parts.