Research Of Friction Mechanism Of Rolling Magnesium Alloy And Contact Interface Material Properties

Most of magnesium alloy were rolled over crystallization temperature,However, It’s prone to mount large-scale adhesive phenomena in the hot rolling process. Adhesive will not only seriously undermine the initial roll stick surface morphology, and will in turn lead to the deterioration of the product surface quality and productivity to reduce the phenomenon of hot-rolled, or even result in shortened life rolls, product obsolescence, and so a series of serious consequences. Therefore, the study analyzes the causes of magnesium alloy during hot rolling adhesion, and impact factors of adhesion phenomena, take measures to prevent sticky friction reduction, improve product surface quality is the pursuit of goals.In this paper, the process of magnesium alloy rolling contact interface material effect on the adhesion properties of the behavior and impact of hot-rolled rolling adhesion related parameters were studied. Research the high temperature oxidation layer morphology and formation time of magnesium alloy and analysis the process of oxide layer formed; By magnesium plate rolling experiments, the annealing temperature, pressure ratio, material throughput, rolling way inferior process parameters on the adhesive and the effect of rolling workpiece surface quality and the change of the friction in the process of rolling, the friction and gelling dynamic coherence theory analysis of hot rolling process.AZ31 magnesium alloy, respectively, in 300 ℃, 350 ℃, 400 ℃, 450 ℃, 400 ℃ annealing heat preservation under 60 min,As temperatures rise, magnesium alloy surface oxidation gradually serious, from the beginning of black dot structure for the development of large black particles, offers rolling adhesion phenomenon when the initial point of nucleation.Rolled at 100℃ annealing temperatures found no sticky roller phenomenon, even before rolling compared to the roughness of the 0.19 to 0.27. Then as the annealing temperature rises to above 200℃, at this time to reach above the recrystallization temperature of magnesium alloys, coherence phenomenon more and more likely to happen. Magnesium plate heated resistance to plastic deformation ability declines with the rising of temperature, 300℃ will happen after falling rapidly. After rolling when the work hardening plays a leading role, the hardness increases, when the dynamic recrystallization happens, hardness decrease.Magnesium plate surface quality with the increase of the lane number processing is a good first, then variation process, shows that after a certain processing in gelling process, the higher the temperature, the inflection point processing to the earlier. At 300 ℃ order working rate reached 25%, magnesium plate surface quality to obtain the best state.Roll and the surface of the rolled piece original state has a great influence on the roll surface quality, material through quantity and influence factors of rolling passes experiment shows that when the roll surface has been gelling magnesium powder layer, if continue rolling, bond is easy to occur, so the time between the need to clean up the roll surface in time.Rolling force is mainly manifested in the process of rolling is magnesium board in the deformation resistance in the process of deformation and deformation resistance is mainly affected by two aspects in the process of deformation, strain hardening and dynamic recrystallization. Prophase work hardening occupy the leading role, the deformation resistance increases, rolling force increases; After the deformation process gives off a lot of calories, material dynamic recrystallization, grain refinement, less resistance to deformation and rolling force is reduced.The change of the friction coefficient is mainly reflected the change of contact state between friction pair, is a process of periodic variations, initially magnesium board broken bond to the roll surface oxidation layer causes in the process of rolling friction coefficient, the roll on the thickening of magnesium glued layer gradually saturated state and peels, friction coefficient decline at this time, then again repeated process of bond- fall off.