本发明属于冶金技术领域，具体地，本发明涉及一种屈服强度500MPa级厚规格热轧H型钢及其制备方法。本发明的热轧H型钢，其化学成分组成按重量百分比为：C：0.10％～0.20％，Si：0.15％～0.30％，Mn：0.8％～1.30％，Nb：0.02％～0.05％，V：0.10％～0.16％，Ni：0.40％～1.0％，P≤0.015％，S≤0.01％，Mo：0.15％～0.35％，Al：≤0.05％，O≤0.004％，N:0.01％～0.02％，其余为Fe和不可避免杂质。本发明采用适合正火轧制的中C含量配合高Ni，高V复合微合金化成分设计，从而得到稳定控制的500MPa级别以上高强韧性海工用热轧H型钢。本发明的H型钢最终组织以细化珠光体+先共析铁素体为主，包含少量的贝氏体组织，通过组织细化和相变强化、沉淀强化，实现H型钢高强度大厚度条件下‑40℃低温冲击韧性大于100J的良好效果。

The invention belongs to the technical field of metallurgy, and particularly relates to a thick hot rolled H-shaped steel with yield strength at 500MPa grade and a preparation method thereof. The hot rolled H-shaped steel is prepared from the following chemical ingredients in percentage by weight: 0.10-0.20 percent of C, 0.15-0.30 percent of Si, 0.8-1.30 percent of Mn, 0.02-0.05 percent of Nb, 0.10-0.16 percent of V, 0.40-1.0 percent of Ni, less than or equal to 0.015 percent of P, less than or equal to 0.01 percent of S, 0.15-0.35 percent of Mo, less than or equal to 0.05 percent of Al, less than or equal to 0.004 percent of O, 0.01-0.02 percent of N and the balance of Fe and inevitable impurities. According to the preparation method, a design of medium C content for normalizing rolling and high Ni and high V composite micro-alloying ingredients is adopted to obtain the high-toughness marine hot rolled H-shaped steel with the yield strength stably controlled at 500MPa or above. The H-shaped steel final tissue takes refined pearlite and proeutectoid ferrite as principle ingredients, contains a small amount of bainite tissues, and has an excellent effect that the low-temperature impact toughness at -40 ℃ below zero is more than 100J under high-strength and big-thickness conditions through tissue refining, hardening through phase transformation and precipitation strengthening.