SPA-H is a high-strength weathering steel with excellent corrosion resistance and high strength. It is mainly used to manufacture steel structures that require extremely high strength and corrosion resistance, such as highway guardrails, railway bridges, vehicles and ships. The chemical composition of SPA-H has a low carbon content and contains a small amount of elements such as nitrogen, hydrogen and phosphorus, which can effectively improve the strength and corrosion resistance of the steel. In addition, SPA-H also contains a small amount of elements such as titanium and niobium, which can refine the grains and improve the strength and hardness of the material. During the manufacturing process, SPA-H needs to be hot-rolled to obtain better material properties. After hot rolling, the grains of SPA-H are finer, the strength and hardness of the material are improved, and it has good plasticity and toughness. In addition, SPA-H has undergone special surface treatment to enhance its corrosion resistance.