Gear steel structure improvement control technology

The invention discloses a gear steel structure improvement control technology. The technology comprises the procedures of molten iron desulfurization and vanadium extraction, semisteel converter smelting, LF refining, RH refining and continuous casting. Nitrogen increasing agent alloy balls are added in the LF process, and a specified cooling solidification control process is implemented in continuous casting. According to the technology, the symmetry of the solidification structure of the gear steel casting blank is remarkably improved, the distance range between the boundary of an equiaxed crystal zone and the surface of the casting blank is reduced to 10-12 mm from 30-40 mm, after the casting blank is rolled into a round bar, the distance range between the boundary of an equiaxed crystal trace zone of the solidification structure and the surface of the round bar is controlled to be smaller than or equal to 4 mm, and the solute segregation degree range (circumferential direction) of the same distance from t