Hot-rolled H-shaped steel and preparation method thereof

The invention relates to the technical field of steel production, in particular to hot-rolled H-shaped steel and a preparation method thereof.The hot-rolled H-shaped steel comprises, by mass, 0.18%-0.24% of C, 0.10%-0.30% of Si, 0.70%-1.15% of Mn, 0.005%-0.011% of Nb, smaller than or equal to 0.018% of P, smaller than or equal to 0.015% of S, smaller than or equal to 0.004% of O and the balance Fe and inevitable impurities, and the preparation method comprises the steps of (1) converter smelting, LF refining and special-shaped blank continuous casting; (2) heating and soaking; (3) rolling the special-shaped blank; and (4) cooling and straightening. According to the method, the alloy manufacturing cost is reduced through the ultra-low niobium microalloying technology, the mechanical property of a product is guaranteed by controlling rolling parameters in the rolling stage, and the production cost of the 355MPa-grade hot-rolled H-shaped steel with the flange thickness of 11-18mm is reduced. 本发明涉及钢材生产技术领域，具体涉及一种