Henan Iron & Steel Group's Cold Rolling Company recently made significant progress in the research and development of 780 MPa duplex steel, with its high-end product CR420/780DP successfully completing trial rolling on the continuous annealing mill. After rigorous testing, the product demonstrated excellent performance across all core technical indicators, with mechanical properties and surface quality precisely meeting design standards. This marks a new breakthrough for the company in the research and production of high-strength steel.

In recent years, the company has continued to cultivate the high-end automotive steel market, focusing its R&D efforts on expanding and upgrading its duplex steel product portfolio. Previously, HC340/590DP grade duplex steel had achieved stable mass production and supply within a thickness range of 0.6 to 2.0 mm, accumulating solid process experience and technical reserves for the development of higher-strength products. The CR420/780DP product rolled in this trial run is currently the highest strength grade product on the cold-rolled production line, primarily targeting fields with stringent material performance requirements, such as automotive internal structural components. The production of this product places extremely high demands on process precision control and overall process stability, representing a comprehensive test of the company's overall technical capabilities.

Faced with the dual challenges of "improving product yield strength" and "reducing the difficulty of rolling processes," the company quickly assembled a dedicated team to tackle these challenges, strengthening cross-departmental collaboration and systematically analyzing the entire production chain from component proportions to final performance. By implementing three key technology optimizations—refining the alloy composition to solidify the material matrix properties, scientifically increasing the reduction rate in the pickling and rolling process, and rationally setting the rapid cooling temperature for the continuous annealing process—the team successfully overcame core technological difficulties such as low tensile strength and difficulty in controlling the rolling process. These measures effectively ensured the uniformity and stability of product performance, ultimately achieving successful small-batch trial production of CR420/780DP, laying a solid foundation for the company's subsequent mass production and market application.