Manufacturing process of Q235NH weathering steel plate

Q235NH weathering steel plate generally adopts the process of fine charging smelting (converter, electric furnace microalloying treatment argon blowing LF refining low superheat continuous casting (feeding rare earth wire) - controlled rolling and controlled cooling. During smelting, scrap steel is added into the furnace together with the furnace charge, smelted according to the conventional process, Deoxidizer and alloy are added after tapping, the molten steel is treated by argon blowing, then cast, and the molten steel after argon blowing and temperature regulating is cast into slab by continuous casting machine. Due to the addition of rare earth elements in the steel, Q235NH weathering steel plate is purified and the inclusion content is greatly reduced.

When phosphorus, copper, chromium, nickel and other trace elements are added to Q235NH weathering steel plate, a dense and strong adhesion protective film will be formed on the steel surface, which will prevent the corrosion from spreading and developing inward, and protect the substrate under the rust layer, so as to slow down the corrosion rate. The amorphous spinel oxide layer with thickness of 50 μ M-100 μ m formed between the rust layer and the substrate is dense and has good adhesion with the substrate metal. Due to the existence of this dense oxide film, the infiltration of oxygen and water into the steel substrate in the atmosphere is prevented, the development of corrosion to the longitudinal depth of the steel material is slowed down, and the atmospheric corrosion resistance of the steel material is greatly improved.

Q235NH weathering steel plate is a steel system that can be used thinly, exposed or simply painted, and can make products resist corrosion and prolong life, save labor and reduce consumption, upgrade and replace.