Hot Deformation Mechanism Of New High-speed Steel Work Roll Blank And Optimization Of Cogging Process

The work roll is the most important part of the rolling mill.Its performance and service time have a great influence on the rolling production efficiency and the quality of the rolled products.Therefore,it is important to study high performance and high quality cold rolling work rolls.In this paper,the research on the hot deformation behavior of a new type of high speed steel material for cold rolling rolls and the process optimization of the blank forging process provide a theoretical basis for the subsequent hot working process.In this paper,the Gleeble-3800 thermal simulator was used to simulate the single-pass hot compression of the high-speed steel for the new cold roll at different strain rates(0.01-10s^-1)and deformation temperature?950-1150°C?.The effects of different deformation rates and temperatures on the rheological curves of the new high-speed steel were analyzed.Considering the influence of the plastic deformation heat generation on the temperature during the hot compression of the sample,the experimental flow stress curve was corrected and the corrected curve was obtained.The trend is the same as the experimental curve,and the deviation between the correction value and the experimental value increases with the increase of strain.The high temperature constitutive model of the material is constructed based on the hyperbolic sinusoidal function,and the thermal activation energy of the new high speed steel is 510.53kJ/mol.Secondly,based on the dynamic material model theory?DMM?,the hot processing map and the safe processing channel are drawn on the new high-speed steel.The observation and analysis of the microstructure of different regions shows that the main cause of the instability is local deformation.The belt is produced and the original grain is severely deformed.The safety zone is suitable for processing due to sufficient recrystallization and uniform organization.The optimum hot working range of the new cold-rolled work roll is between 1100 and 1150°C.The rate is between 0.01 and 0.1 s^-1.Finally,the DEFORM software was used to simulate the blanking process of the new high-speed steel for cold rolling.By simulating the changes of stress field,strain field and damage value under different reduction rates and feed rates,the effects of different processes on improving the internal quality of the blank were studied.The deformation of the anvil area was solved by adjusting the amount of wrong anvil.The problem is that when the reduction ratio is 25%,the feed amount is 0.8 times the blank height,and the wrong anvil amount is 0.5 times the feed amount,the degree of deformation and deformation uniformity of the blank is the best,and the forging effect is the best.