Tribology Behaviors Of Materials Based On Three-Planetary Rolling Process

Three planetary rolling process has been widely applied to the processing of non-ferrous metal tubes.During the rolling process,the rollers may suffer from cracks,adhesion and pits,which will seriously affect the quality of the products.These defects mainly come from relative movement and can affect the service span of rollers.Therefore,it is very important to conduct in-depth research on the friction and wear behavior of workpiece and die in three planetary rolling process.The main points and results of this dissertation are below:(1)A three-dimensional coupled thermo-mechanical model of three planetary rolling process was established by finite element(FE)method,and the FE analysis of tube billet from biting to stable rolling was realized.The deformation mode,temperature field and force condition of the three planetary rolling process were analyzed.The results were the instructions for the ring-block wear tests.(2)Ring-block wear test were conducted with a ring of H70 copper alloy and a block of GH4169 super alloy or 3Cr2W8V tool steel.The aim of these experiments is to investigate the effect of temperature during wear tests without lubrication.The forced cooling wear tests were conducted using liquid N2,considering its cooling effect at the contact area and no effect of lubrication.Through the analysis of interface temperature,wear mass,wear morphology,hardness of worn surface,etc.,the wear mechanism of GH4169 and 3Cr2W8V was illustrated.The results are instructions for reducing wear and improving roller materials.(3)Finite element model of ring-block wear test was established.Heat transfer coefficient(HTC)value is the variable to adjust interface heat transfer.The wear of block materials were calculated respectively,and the relationship between the wear volume and the friction heat under different external conditions was obtained.Basted on these calculations,the wear mechanisms of GH4169 and 3Cr2W8V under different temperatures are obtained using the product of strength and elongation ?UTS × ?UE.The relationship of wear and high temperature deformation behaviors of GH4169 and 3Cr2W8V were investigated.