Is the product made of weathering steel really easy to use

Atmospheric corrosion resistant steel, also known as weathering steel, is a kind of low alloy steel made by adding a certain amount of alloying elements to ordinary steel, the main alloy composition is Cu, P, Cr, Ni and other elements.

essential information

Atmospheric corrosion resistant steel (that is, weathering steel) refers to a low alloy steel with good atmospheric corrosion resistance made by adding a certain amount of Cu, P, C or Ni, Mo, Nb, Ti and other alloying elements in steel. In the industrial and rural atmospheric environment, the weathering steel forms a dense and stable oxide protective film on the surface of its matrix, hindering the entry of corrosive media, and has excellent atmospheric corrosion resistance and other properties, while the rust layer formed by corrosion on the surface of the carbon steel matrix is loose and has micro cracks, which can not really play a protective role on the matrix steel

mechanism of corrosion

From the effect of corrosion products on the corrosion process, the atmospheric corrosion of steel is a process of electrochemical reaction of oxygen in the air through the rust layer in the presence of water film. The rust layer is composed of loose outer rust layer and dense inner rust layer, and the alloying elements in steel are mainly affected by the inner rust layer. The enrichment of Cu, P and Cr dense inner rust layer can be observed in the corrosion products of weathering resistant steel. The higher corrosion resistance of weathering resistant steel is related to the high impedance of the inner rust layer, the density of the inner rust layer, the finer grain size and the enrichment of Cu and P. The presence of this dense inner rust layer is reflected in the electrochemical behavior of the steel that the anode process is blocked. This process of gradually improving its densification in the corrosion process just shows that the longer the time, the stronger the corrosion resistance.

atmospheric corrosion

From a global perspective, the main composition of the atmosphere is basically unchanged. According to the experimental determination, the composition of the air by volume is about: nitrogen 78%, oxygen 21%, noble gases 0.94%, carbon dioxide 0.03%, other gases and impurities 0.03% [4]. Due to the natural location, climate and other conditions and man-made environmental pollution, the composition of the atmosphere has become complex and diverse, and some harmful components have a gradual increase trend. In particular, global acid rain caused by sulfur dioxide and nitrogen dioxide in the air has exacerbated the corrosion of steel materials, although there are no naturally occurring sulfur dioxide and nitrogen dioxide. However, the vast majority of these basic air pollutants are produced by human activities. Once the sulfur dioxide and nitrogen dioxide pollution gases emitted by humans enter the atmosphere, they may be converted into secondary pollutants nitric acid and sulfuric acid, which are easily soluble in water and form acid water droplets to return to the ground to form acid rain, acid snow, etc.