Optimization design of process parameters for cold and hot composite roll forming of the AHSS square tube using response surface methodology

Advanced high-strength steel (AHSS) is a highly competitive material for the automobile industry to resolve challenge of weight reduction and passenger safety. Cold hot composite roll forming newly developed manufacturing technology, which aims overcome defects such as microcrack, severe work hardening, thickness reduction, large corner radius in traditional cold process AHSS. In this paper, mathematical models that represent effect line velocity, heating power, deformation amount on yield strength, outer radius, microcrack length section roll-formed AHSS square tube are investigated by response surface methodology with Box-Behnken design. The analysis variance shows linear velocity has greatest influence three responses, followed power amount. Furthermore, experimental verification carried out under optimal combination parameters manufacture desired performance. Compared tube, product strength elongation increased 53%, 60%, decreased 94%, defect not generated. average magnitude errors between predicted actual values about 5%, implies optimization design accurate reliable.