The High-Speed Wire Mill has successfully developed the HRB500E steel grade and completed its rolling process smoothly.

Led by the Technology Center, the Steelmaking Plant and the High-Speed Wire Mill collaborated to tackle key technical challenges. Through precise optimization of the steel's chemical composition, the vanadium-nitrogen ratio in the steel was achieved at an optimal level, fully exerting the dual effects of precipitation strengthening and grain refinement strengthening of vanadium carbonitride.

Meanwhile, tailored precise process parameters for the entire 流程 of heating, rolling, and cooling were formulated based on the characteristics of the production line equipment. Key indicators such as rolling start temperature, laying temperature, and cooling rate were incorporated into closed-loop control. As a result, a uniform and fine ferrite + pearlite metallographic structure was successfully obtained. Multiple technical difficulties, including the precise design of vanadium-nitrogen microalloying, temperature-controlled rolling, and precise controlled cooling, were overcome, and HRB500E seismic-resistant deformed steel bars (coiled rebar) in compliance with national standards were successfully produced.

Professional testing shows that the minimum yield strength of Φ8-10mm products reaches 550MPa, 50MPa higher than the national standard requirement. The average total elongation at maximum force reaches 14.5%, and core seismic indicators such as the strength-yield ratio and yield-yield ratio are all significantly superior to the national standards.

The successful development and rolling of the HRB500E steel grade marks an important progress for the enterprise in the R&D and production of high-strength construction steel, laying a solid technical and practical foundation for the large-scale and standardized production of high-end seismic-resistant steel bars.