Widening Model And Experimental Research In The Rolling Process Of Stainless Steel Bars

Stainless steel products are widely used in marine engineering,petrochemical,aerospace and other fields.Its materials not only have high strength,good corrosion resistance,and good heat resistance,but also facilitate plastic processing and welding;Pass rolling is a bar forming process,which can effectively control the product size and meet the production requirements of products of different specifications.However,in the rolling process of stainless steel bars,it is easy to deform unevenly,causing defects such as ears and under-filling of the rolled pieces,and eventually lead to out-of-tolerance phenomenon in the bar-rolled products.In this paper,95Cr18 martensitic stainless steel is taken as the research object.Through theoretical analysis,numerical simulation and rolling experiment,the cross-sectional area,equivalent radius of the roll and the width extension model of the rolled piece during the bar rolling process are studied,and the 95Cr18 martensitic stainless steel is obtained.Based on Shinokura Tsuneki’s modified widening model for the rolling process of bulk stainless steel bars and detailed analysis of the widening law,the research results have important practical application value for improving the quality of bar rolled products.First,carry out thermal simulation experiments of 95Cr18 martensitic stainless steel under different hot compression processes to obtain its flow stress curve data.Based on the flow stress curve,the high-temperature deformation constitutive equation and hot working diagram of 95Cr18 martensitic stainless steel are constructed;Through the analysis of the high-temperature deformation constitutive equation and the thermal processing diagram,the temperature process window of the stainless steel bar hot rolling is obtained,which provides basic data for the finite element numerical simulation and the widening calculation.Secondly,the accurate theoretical analysis of the cross-sectional area of each pass of the typical stainless steel bar rolling was carried out,and the accurate calculation of the relevant process model was carried out,And discussed and analyzed the widening model,It shows that accurate cross-sectional area calculation improves the calculation accuracy of subsequent process parameters,makes the calculation results of equivalent radius and width of the roll closer to the actual size during the rolling process,and provides more accurate basic data support for the calculation of rolling width.Finally,the finite element simulation of the 95Cr18 martensitic stainless steel bar rolling process was carried out,and the stress,strain distribution and spreading law of the rolled piece during the rolling process of different process parameters were explored.Based on Shinokura Tsuneki’s spreading formula,a revised 95Cr18 martensitic stainless steel spreading model was obtained,and the reliability of the revised model was further verified through bar rolling experiments.