Effect of Alloying Elements on ASTM A 709 Gr.50W Weathering Steel Weathering Resistance

The key to the atmospheric corrosion resistance of ASTM A 709 Gr.50W weathering steel is the protective rust layer on the outside of the steel matrix, whose physical and chemical properties determine the resistance to atmospheric corrosion.

ASTM A 709 Gr.50W weathering steel will also be corroded in the atmosphere, and the rust layer will thicken over time, but compared with ordinary carbon steel, the rust layer generated on the surface of ASTM A 709 Gr.50W weathering steel is more dense and cracked It has fewer defects such as pores and ions, and has a certain ion selectivity, which can well block a series of corrosion-promoting factors such as water vapor, chloride ions and acid sulfides in the atmosphere, reduce the penetration of corrosive substances into the substrate, and further reduce the Corrosion rate, increase the service life of ASTM A 709 Gr. 50W Weathering Steel.

Alloying elements play a key role in the formation of the protective rust layer of ASTM A 709 Gr.50W weathering steel, usually these alloying elements include Cu, Cr, Ni, P, Mo, RE, etc.