Weatherproof steel, that is, atmospheric corrosion resistant steel, is a series of low alloy steel between ordinary steel and stainless steel. Weatherproof steel is mainly used in railway, vehicles, bridges, towers, photovoltaic, high-speed engineering and other steel structures exposed to the atmosphere for a long time. It is used to manufacture structural parts such as containers, railway vehicles, oil derricks, harbour buildings, oil platforms and containers containing hydrogen sulfide corrosion media in chemical and petroleum equipment.
Weatherproof steels generally adopt refining-smelting (converter, electric furnace-microalloying treatment-argon blowing-LF refining-low superheat continuous casting (feeding rare earth wire) - controlled rolling and cooling process. During smelting, scrap steel is added into the furnace together with burden, and is smelted according to conventional process. After tapping, deoxidizer and alloy are added. After argon blowing treatment, molten steel is casted immediately. After argon blowing, the molten steel is casted into slab by continuous caster.