Casting And Forging Process And Numerical Simulation Technique Of Large Back-up Roll

Production Capacity of heavy Castings and Forgings represent thedevelopmental level of a country’s heavy industry, an important industry whichpromotes national development. With the rapid development of industrial technology,The heavy Castings and Forgings have been applied to the field of Petrochemicals,Mining machinery, Nuclear island of nuclear power, aerospace, shipbuildingequipment, etc. With Poor working conditions, high in loading and high safetyperformance, therefore the study of large castings and forgings is of great significance.The processing and numerical simulation technique of Large Back-up Roll are studiedmainly in this article.The filling and solidification processes of Back-up Roll ingot was simulated withthe software ProCAST, and the positions of shrinkage porosity and cavity aboutdifferent riser height were forecasted. At the same time, the temperature field of thecomplete solidification and ingot defect were researched when it had the exothermicpowder or not. The simulation results show850mm of the riser height and theexothermic powder make the final solidification area concentrate inside the riser,which enhances the role of the riser.The hot compression deformation behaviors of70Cr3Mo steel were studied in thedifferent deformation conditions on Gleeble1500thermo-simulation machine, then,to observe the change of the Microstructure, the compressed samples were used asmetallurgical analysis. According to the stress-strain curve, the hot deformationactivation energy, the constitutive equations, the dynamic recrystallization criticalstrain cunder different deformation conditions and the processing map at the truestrain of0.5were calculated. The processing map shows there are two Instability zones of hot deformation for the70Cr3Mo Steel, and the safest area: temperature range of1000~1150℃and strain rate range of0.1~0.36s1. The experimental results canprovide the scientific basis for developing a reasonable process when70Cr3Mo steel isthermoplastic deformation.WHF forging stretching process is used to forge the Back-up Roll. The process ofUpsetting and Stretching are simulated with the software Deform. The center offorging piece comes into being compressive stress, which is conducive to close cavity.By simulating different anvil width during stretching process and analyzingtemperature distribution, equivalent strain and three-dimensional stress, the forgingprocess of the heavy Back-up roller forging is optimized.The research findings of Composite Casting and Forging Hot Forming Process ofthe Back-up roller in the paper lay a theoretical foundation for producing the qualifiedforgings satisfy the requirement of size precision and internal quality.