Recently, Shougang’s highest-strength cold-formed automobile sheets HC820/1180DP came off the assembly line successfully in Jingtang Company, marking that Shougang super-high-strength automobile sheet products fully entered the giga camp, and Shougang has become one of the few super-high-strength automobile sheet suppliers in the world.

A lightweight and high-strength car body structure which can reduce energy consumption and emissions and improve passengers’ safety, is the main direction of the development of the automobile industry. To achieve this goal, the use of thin and super-high-strength steel is the best solution. The domestic automobile industry’s demand for super-high-strength automobile sheets of good formability increases year by year, but the automobile sheet of over 1,000MPa   still needs to be imported. The ability to provide advanced super-high-strength steel products of more than 1,000MPa has become an important symbol to measure R&D manufacturing level of iron and steel enterprises.

Since the beginning of this year, the “super-high-strength automobile sheet team” of Shougang Research Institute of Technology, led by chief expert Dr. Kuang Shuang, has taken the lead to actively expand the super-high-strength automobile sheet market with KMPa level, and has carried out customized product development based on the needs of customers to help upgrade the product structure of Shougang. The order of this newly developed HC820/1180DP dual-phase steel product comes from the joint venture factory of a world-famous automobile brand enterprise in China, and the goal is to switch the European imported steel sheet and realize the localization of the material. On the basis of dissecting the body parts of the material, analyzing the deformation characteristics, welding characteristics and other requirements, the researchers of the key research group conducted pilot research and development, focusing on the problem of the deterioration of ductility under super-high strength. Through the fine design of the target microstructure, the alloy system matching and rolling annealing process were developed. The actual yield strength and tensile strength of the developed materials reached 1,000MPa and 1,300MPa respectively, which has quite high requirements for the control ability of the equipment‘s automation and the experience level of the operator. In order to complete the order production successfully, the researchers of the Research Institute of Technology worked with the technicians of the Jingtang Company to further optimize a furnace temperature control model, deeply controlling the key links, such as the cleanliness of the strip steel and furnace inside atmosphere. After repeated tests and continuous improvement of the process, its performance, shape accuracy, surface finish, etc. are effectively ensured. The product came off the assembly line successfully, which laid a solid foundation for Shougang to improve its brand impact of the super-high-strength automobile sheet.