Simulation And Experimental On Hot Ring Rolling Process Of 6061 Aluminum Alloy Casting Blank

With the rapid development of major technical fields such as aerospace,wind power and ocean-going ships,due to the superior properties of light weight,heat conduction and corr osion resistance,aluminum alloy ring parts as the key connection and supporting components are widely used in major equipments including wind power towers,gas pipelines and energy s torage containers.The traditional production process of aluminum alloy ring parts has outstanding problems such as lengthy process,large equipment investment,seriously material waste and low efficiency.Thus,in recent years,with the financial support of the National Natural Science Foundation of China(No.51875383)and other projects,the compact cast-rolling compound process based on a casting ring blank are studied.The casting ring blank after only one heating is hot-rolled into rings.The shortcomings in the current process are solved,and it is used in the production of bearings and flanges.In this study,a 6061 aluminum alloy is taken as the research object.By combination of theoretical analysis,simulation and experiment,the hot ring rolling of 6061 aluminum casting blank was studied.And then the microstructure evolution and mechanical properties of the hot-rolled ring were analyzed.The three-dimensional finite element model of casting 6061 aluminum ring blank during hot rolling on the ABAQUS platform was developed.The analysis of thermal-mechanical coupling simulation was carried out.The effects of key parameters including feeding rate of idle roll,initial temperature of casting ring blank,friction coefficient on the equivalent strain field,temperature field distribution and its change during hot rolling,as well as the change of rolling force and rolling torque were studied in detail.The main results are as follows: 1)In the hot ring rolling,the equivalent plastic strain in the thickness of the ring increases by steps.The increase trend in the middle-layer is slow,and the equivalent strain is smaller compared with other areas.The largest equivalent strain is found in the surface-layers.The equivalent strains in the upper,down,inner and outer-surfaces show a gradual increased distribution.2)In the hot ring rolling,the temperature of the surface-layers of the ring present a downward trend,and the middle-layer still maintains a high temperature,which implies that the temperature in the middle-layer is the highest and the temperature in the edge area is the lowest.The temperature from the middle-layer to the upper,lower and inner and outer-surfaces presents a gradual decreased distribution.3)The effects of parameters on fields and forces is,the feeding rate increase,the more uniform the equivalent strain and temperature distribution of the ring,and the increase in force consumption.The initial temperature of the casting ring increases,the better the uniformity of the equivalent strain distribution,while the lower the uniformity of the temperature distribution,the greater the energy consumption.The friction coefficient has no obvious effect on the uniformity of the hot-rolled ring.Based on the simulation results of hot ring rolling,the experiment of 6061 aluminum casting ring blank was conducted on the D51-350 ring rolling machine.The results indicate that the relatively precise shapes and geometrical dimensions of the hot-rolled ring are achieved,and the maximum deviation of the outer diameter is within 5mm.The grain sizes of the hot-rolled rings are found to be 50-80?m at different feeding rates of i dle roll and the initial temperatures of the casting ring blank.The uniformity of the microstructure distribution in the radial thickness is better.The mechanical properties of the ring meet the requirements of the standard.Thus,it is feasible to fabricate aluminum rings by the compact cast-rolling compound process based on the casting ring blank.