Q355NH is a weathering structural steel, which is a low alloy steel series between ordinary steel and stainless steel. It is made of ordinary carbon steel with a small amount of copper, nickel and other corrosion-resistant elements. Wear resistance, high temperature resistance, fatigue resistance and other characteristics; weather resistance is 2 to 8 times that of ordinary carbon steel, and the coating performance is 1.5 to 10 times that of ordinary carbon steel. Mainly used for steel structures exposed to the atmosphere for a long time, such as railway vehicles, bridges, iron towers, etc. Q355GNH weathering steel is a steel that forms a protective layer on the surface of the metal matrix by adding a small amount of alloying elements such as Cu, P, Cr, and Ni to improve the atmospheric corrosion resistance. Weathering steel has the characteristics of high-quality steel in terms of strength, toughness, plasticity, forming, welding and cutting, wear resistance, high temperature resist…