Recently, Pangang Research Institute, together with Xichang Steel and Vanadium and Chongqing High-Strength Steel, completed the full-process batch industrial test of hot-base galvanized complex phase steel H780CP, overcame technical difficulties such as high hole expansion, and successfully developed hot-base galvanized complex phase steel for the first time, adding a new member to Panzhihua Iron and Steel's ultra-high strength steel varieties.
In recent years, with the implementation of the "dual carbon" strategy and increasingly stringent automobile safety regulations, the requirements for lightweight and high-safety automobile steel have become increasingly higher, and ultra-high-strength steels such as complex phase steel have been widely used. Compared with other high-strength steels, hot-dip galvanized complex phase steel has higher yield strength and work hardening characteristics, higher energy absorption capacity, and higher residual deformation. It is particularly suitable for automotive parts that require good impact resistance, such as automotive chassis parts, door anti-collision bars, seat slides, door sill reinforcements, etc. Hot-dip galvanized complex phase steel is a high-strength steel variety that domestic steel companies have focused on developing in recent years, but due to the high-quality performance requirements of the product, only a few companies have achieved industrial production.
In response to the requirements of high hole expansion and high durability, the project team used Ti microalloying to replace traditional phase transformation strengthening based on the composition of C-Si-Mn and prepared a complex phase structure dominated by bainite and ferrite through controlled rolling and controlled cooling, achieving a hole expansion rate of more than 45% for hot-base galvanized complex phase steel. The product has been successfully applied to a certain automobile manufacturer and is in good condition.
The successful development of Pangang hot-dip galvanized complex phase steel H780CP has improved the variety structure of Panzhihua automobile steel, promoted the brand building of Panzhihua automobile steel, promoted the technological progress of domestic ultra-high strength steel, and contributed to the green development of automobile steel.