Microstructural Transformation Law and Production Practice of Hot-Rolled H-Section Steel in V-Ti Composition System

To investigate the influence of the V-Ti composition system on the material strength grade and quality grade, deformation thermal simulation tests were conducted to study the microstructural transformation law. Combined with actual production trials, in this paper, field trials and performance testing were carried out on hot-rolled H-section steel of typical column member specifications for building steel structures. The results indicated that when producing H400×400 hot-rolled H-section using a V-Ti alloy system, with a flange reduction of 60% in the universal stand, a rolling cooling rate of 0.5℃/s to 1℃/s, and rolling temperature control at 940～960℃, the product could achieve a strength grade of Q420 and a low-temperature ductile-to-brittle transition temperature as low as -50℃. Additionally, considering practical production cost control, synchronously producing small batches of hot-rolled H-section with the same steel grade (Q355 to Q420) but different quality levels (B to E grades) demonstrates economic feasibility, providing technical support for efficient production of hot-rolled H-section steel and material selection for standard components.