Effect of alloying elements on atmospheric corrosion resistance of weathering steel

The improvement of corrosion resistance of weathering steel benefits from the addition of alloying elements. Different alloy elements have different effects on corrosion resistance, and different results may be obtained in different environments.

The influence of alloying elements on atmospheric corrosion resistance of weathering steel is as follows:

1. Cu and P elements: Cu has the most obvious effect on the weatherability of the alloy. When Cu and P act together, the effect is more significant.

2. Cr Element: the existence of Cr can obviously accelerate the development of electrochemical corrosion products to thermodynamic stable state.

3. Ni and CO: Ni is a relatively stable element. It is found that low alloy steel containing 1% - 3% Ni or Co has better corrosion resistance in saline atmosphere.

4. Si element: weathering steel contains a large amount of Si and a small amount of P, which can increase the content of paramagnetic a-FeOOH in the protective rust layer, refine a-FeOOH, and reduce the corrosion rate of the material.

5. Nb element: the grain refinement of Nb can improve the atmospheric corrosion resistance of weathering steel.

6. RE element: the addition of RE element can refine the grain, change the existing state of inclusions in the steel, reduce the number of harmful large inclusions and reduce the corrosion source, so as to improve the atmospheric corrosion resistance of the weathering steel.