Weathering steel for welded structure

1. High weathering steel

High weather-resistant structural steel is actually added with a small amount of copper, phosphorus, chromium, and nickel to form a protective layer on the surface of the metal collective to improve the steel's resistance to atmospheric corrosion. A small amount of molybdenum, niobium, and vanadium can also be added. , titanium, zirconium and other elements to refine the grain, improve the mechanical properties of the steel, improve the strength and toughness of the steel, reduce the brittle transition temperature, and make it have better brittle fracture resistance.

2. Weathering steel for welded structure

The elements added to the steel, except for phosphorus, are basically the same as those of the high weather resistance structural steel, and their functions are also the same, and improve the welding performance.

The principle of weathering steel: After adding trace elements such as phosphorus, copper, chromium, and nickel to the steel, a dense and highly adhesive protective film is formed on the surface of the steel, which prevents the inward diffusion and development of rust, and protects the substrate under the rust layer. its corrosion rate.

The amorphous spinel oxide layer with a thickness of about 50 μm to 100 μm formed between the rust layer and the substrate is dense and has good adhesion to the substrate metal. Due to the existence of this dense oxide film, it prevents oxygen and oxygen in the atmosphere. The infiltration of water into the steel matrix slows down the deep development of corrosion into the steel material and greatly improves the atmospheric corrosion resistance of the steel material.

Weathering steel is a steel system that can be used for thinning, exposed use or simplified coating, so that products can resist corrosion and prolong life, save labor, reduce consumption, and upgrade. Continuous development and innovation of the steel system.