Research Of Pass Optimum Of Bar Tandem Rolling Of T91 Steel

The steel of T91 has become one of the most widely used in heat pipe material due to its good price ratio and process performance.This paper has studied the process of T91 steel,and developed the experiment and research of T91 rolling forming technology based on Shanghai Baosteel group.The paper carried out the thermal simulation experiments using Gleeble-1500 thermal simulation test machine in the research and experiment,and analyzed the influence of forming temperature,deformation rate and deformation degee on the deformation resistance of T91 steel.T91 steel is a rate sensitive material in high temperature region, its deformations stress is increased rapidly with the increase of deformatiom rate only when the temperature is above 800 C. Based on the results of previous studies,the T91 plastic constitutive equation was established through analyzed the relationship between temperature,strain rate,flow stress and activation energy.In the determination of friction coefficient,the maximum bite angle method is adopted in this article.Through compared the results and the empirical estimates.it showed they are very approximative that turned out the friction coeffient valid.The article carried out the numerical simulation of T91 rolling forming process based on the T91 plastic constitutive equation, the friction coefficient of friction experiment, and the ABAQUS finite element software,then we got the distribution of the stress field, strain field and temperature field analysis, forming temperature, rolling speed, friction conditions and other factors on the forming of material flow, defect formation and the influence of stress and strain etc.finally,we confirmed the rolling process of T91 that provided the theoretical basis for the actual production,and at the same time,has laid a solid foundation for the future use of rolling steel.