Performance investigation of magnetorheological finishing of rolls surface in cold rolling process

摘要

Cold rolling is one of the most vital manufacturing operation in the sheet metal industries. It produces controlled size and accurate thinner gauge components with a smooth surface. In cold rolling operation, the rolls are the most important component. If rolls surface gets finished at a greater level, a smooth surface on the final products can be achieved. This may improve functional performance for their practical use. To accomplish this requirement, the magnetorheological (MR) finishing process using rectangular-rotating tool core tip has been used to finish the external surface of the rolls. The process parameters such as roll workpiece rotation, tool feed, tool rotation, working gap and current intensity of the electromagnet and composition of MR polishing fluid are considered to investigate the performance of cold rolling rolls using the rectangular-rotating core tip-based MR finishing process. For effectively performing the MR finishing operation, the optimum process parameters are predicted by using the response surface methodology. These optimum parameters have been used to perform the MR finishing on the external surface of the industrial H13 die steel rolls as used in cold rolling process. The surface roughness gets reduced to 18 nm from the initial ground roughness value of 200 nm. After the MR finishing operation, the cold rolling rolls are tested its functional performance in the industry. The performance of the MR finished rolls surface is investigated as compared with the ground rolls surface. Experimentally and theoretically analyse the roll force, roll torque, and power consumption on use of before and after MR finished rolls surface in cold rolling operation. Almost all the performance parameters with MR finished rolls surface are found in favour of improvement in functional operation during its actual application in the cold rolling process.