Effect of chemical elements on JIS G3125 SPA-H steel plate

The results show that copper is the most important factor affecting the weather resistance of JIS G3125 SPA-H steel plate, while nickel has little effect on it. Copper acts as an active cathode in JIS G3125 SPA-H steel plate.

The copper precipitated from the surface of copper bearing steel can promote the anodic passivation of JIS G3125 SPA-H steel plate, form a dense and good adhesion antirust protective layer, and reduce the corrosion rate of matrix in external media.

The addition of P helps to improve the corrosion resistance of JIS G3125 SPA-H steel plate. Phosphorus is an anode depolarizer, which can promote the uniform dissolution and corrosion of JIS G3125 SPA-H steel plate surface, increase the polarization resistance of rust layer on the steel base surface, and slow down the speed of corrosion medium entering the substrate of JIS G3125 SPA-H steel plate.