| There is a close relationship between the high speed development of the automobile industry and the steel industry.Lightweight and higher safety performance is the goal of the future development of the car, meanwhile the requirements of the automotive steel is also constantly upgrading. The development of high strength cold rolling steels sheet using in automobile is attached great importance to the many countries in the world, the dual phase steel with low yield, high tensile strength and low yield strength than the rate and force strain curve smoothing and other advantages, high initial work hardening rate, high elongation, become a kind of excellent performance of high strength model of stamping forming steel is used in modern automobiles is an important part of the steel. Therefore, it is an important symbol to measure the comprehensive strength of modern iron and steel enterprises,whether the production process is long, the technology is complex, the production management and technical requirements are strict, and the product technology content is high. The first echelon of the iron and steel enterprises in the world take the cold rolling automobile steel as the most important product development and production.In this article,we take the cold rolling dual phase steel DP590 and DP780 as the research object, through optimizing the composition design, steel characteristics and laboratory tests identified preliminary production plan, and through the industrial production,gradually optimize the chemical composition, hot rolling, cold rolling and annealing process, thereby making the reasonable production processing point of cold rolling dual phase steel. Through the practice of industrial production, some dual phase steel DP590 and DP780 products have met the requirements of high grade automobile steels in Ansteel, and reached the advanced level of the same level at home and abroad,the main research contents are as follows:1) The determination of the content of alloying elements, the design of the tensile strength and yield strength, and the determination of the actual composition of the double phase steel.2)Dual phase steels are characteristics of Austenite Continuous Cooling Transformation of, under different cooling speeds curve turning point statistics,thermal expansion plastic research, thermal deformation resistance research, work hardening rate measurement.3)Determination of hot rolling process, cold rolling process and annealing process of double phase steel laboratory rolling and annealing. Observation of microstructure of hot rolled and cold rolled. Influence factors of typical mechanicalproperties such as yield strength ratio, n value, r value and so on. |
