Experimental Research On Hot-forming Process Parameters Of Automotive High Strength Steel

Hot forming technology of high strength steel is a new developed forming technology combined with metal heat treatment technology and metal plastic forming theory. Because of the high strength steel widely used in the automobile industry and the monopoly of foreign technology, so hot forming technology of high strength steel is strongly supported and encouraged by our country, as well as given great importance to attaches by the academic community. Hot forming technology of high strength steel has broad market demand and strongly vitality.Now, automobile industry is developed toward green, environmentally friendly, safe, high performance, and vehicle weight reduction is an important way to achieve energy saving and environmental protection. The high strength steel in automobile applications realizes automobile lightweight and energy saving, at the same time improves the vehicle crash safety. Temperature and cooling rate are important factors that impact hot forming of high strength steel,22MnB5is selected as the research object in this article. The theme is the effect of different cooling rates on22MnB5microstructure and mechanical properties. The optimal heat preservation time is determined by studying the impact of different holding time on the mechanical properties of22MnB5. Material thickness direction of hardness experiment after quenching found material hardness in the thickness direction showing the intermediate hard-soft on both sides of nearly symmetric distribution of metal composite structure.22MnB5sheet quenched under different cooling rates, ultimately the optimal cooling rate range of the thickness of2.0mm sheet in the mold is defined through tensile test, V-shaped bending test, hardness and microscopic analysis, meanwhile, the relationship between hardness and tensile strength is obtained. High strength steel has high tensile strength and yield strength but poor toughness. How to improve its toughness is another important topic. Quenching the different regions of22MnB5in different ways, the hardness of transition zone of the different cooling rates shows a gradient increasing trend through mechanical and hardness tests. The transition region material tensile strength increases while the toughness maintains a high level. The importance of the research realizes vehicle in different regions with materials of different strength and hardness. The optimum parameters of hot forming technology of high strength steel are determined and play a guiding role in the actual production process of hot forming.