The Research On The Technology Of The Usage And Maintenance For Back-up Roll In Hot Strip Mill At Baosteel

The paper took the mass production of 2050 HSM as background.To avoid catastrophic fatigue spalling due to over wear of back up roll,off-line simulation based on effect function method was carried out,and finite element analysis was further carried out to simulate and verify the safety of the rolls with prolonged service schedule.The paper also researched on the set up of reasonable dressing practices and scientific using and maintenance technology.The following are the details.(1)the influence of different factors on the contact stress between work roll and back up roll was analysed by means of off-line simulation program which is based on effect function nethod and elastic deformation theory,to provide theoretical guidance for the optimization of the shape of the back up roll.Through the further finite element calculation model simulation and verification,the newly designed back up roll curve can realize the even distribution of contact stress.the wear and local fatigue of the back up roll were reduced,to ensure the safe use of back-up rolls during service,and prolong the service schedule of back up rolls.(2)Optimizing amounts of grinding.The dressing amount is determined according to hardness test and crack inspection,which replace the method according to rolling tonnage and minimum dressing amount.(3)Teaming back-up roll technology.Evaluate the rolls based on manufacturing process,hardness,roll maker,diameter,performance data,the performance of each roll decides which stand for the roll to be put in.(4)Roll incident analyzing technology.Classify the different failure,revitalize the roll with defects.Through the research on the tracking up of in-use back-up roll,the dressings practice,service schedule,roll failures analysis,the back-up roll is used more safely,the service schedule longer,the tonnage per millimeter larger.The value-added Cr5 back up roll is used successfully,the process cost is decreased.