Influence of elements in weather resistant steel plate on corrosion resistance

Like ordinary steel plate, weather resistant steel plate will produce a layer of rust after reacting with the atmosphere. However, this layer of rust is an oxide film, which is firmly attached to the surface of weather resistant steel plate to prevent further reaction between the base and the atmosphere, so the weather resistant steel plate has good weatherproof performance. We all know that some weathering elements are added to ordinary carbon steel in the process of smelting weather resistant steel plate. How do these weathering elements affect the corrosion resistance of steel?

1. Carbon: Carbon is not conducive to atmospheric corrosion resistance of steel, while carbon has adverse effects on weldability, cold brittleness and stamping performance of weather resistant steel plate.

2. Manganese: Manganese can improve the corrosion resistance of steel to marine atmosphere, but it has no effect on the corrosion resistance in industrial atmosphere.

3. Phosphorus: Phosphorus is one of the most effective alloying elements to improve the atmospheric corrosion resistance of steel. Phosphorus can dissolve evenly in steel, which helps to form a compact protective film on the surface of weather resistant steel plate and prevent its interior from atmospheric corrosion.

4. Copper: The effect of copper on counteracting the harmful effect of sulfur in steel is obvious. The higher the sulfur content in steel, the more remarkable the relative effect of copper on reducing the corrosion sour current is. This is because copper and sulfur produce insoluble sulfides.

The above knowledge shows that different elements have different effects on the corrosion resistance of weather resistant steel plate, and their chemical mechanisms are different. In smelting weather resistant steel plate, attention should also be paid to the addition amount and proportion of various elements. If not properly controlled, good weathering resistance will not be achieved.