Corroded steel plate application process

Corroded steel plates are more common in today's life. Corrosion of any metal begins at the surface. In some cases, such as aluminum, an oxide layer forms on the surface, which acts as a barrier to further contact with oxygen, thus inhibiting corrosion. A layer of iron oxide in dry air, too thin to be seen with the naked eye, protects the iron. However, in the presence of moisture, iron oxide hydroxides form and the iron becomes porous, which can absorb oxygen and allow corrosion to proceed. Efforts have been made for decades to achieve or inhibit corrosion of metals by adding other substances to pure metals, with varying degrees of success. Traces added to iron may accelerate the corrosion rate, but some other substances may inhibit corrosion. Adding aluminum to brass makes it more resistant to corrosion. The disadvantages of using non-corrosive materials to solve corrosion problems are the tendency to lack physical properties compared to the original metal, or the increased cost due to the cost of the alloy.

Secondly, a common anti-corrosion method for rusted steel plates is to add a durable surface coating (or coating) to the metal to be protected. The materials used in these coatings vary, but the most commonly used are paints, plastics, rubber, ceramics and other metals that are applied to surfaces such as aluminum, zinc through various methods (such as electroplating, hot-dip galvanizing, spraying, etc.) , chromium or nickel. When using protective coating systems to protect metal structures from corrosion, everyone involved, from component designers to painters to paint inspectors, must have at least a basic understanding of corrosion and its influencing factors. This knowledge of chemistry is essential.

Corroded steel plate

3. Introduce the history of corroded steel plates. The development of weathering steel originated in Europe and the United States. As early as 1900, European and American scientists discovered that Cu could improve the corrosion resistance of steel in the atmosphere. In 1961, the American Society for Testing and Materials (ASTM) began to study atmospheric corrosion. In the 1930s, USSteel Corporation first developed Corten steel, a corrosion-resistant, high-tensile-strength, copper-containing low-alloy steel that was uncoated in the 1960s. The paint is applied directly to buildings and bridges. Applications are common: Corten A series with high P, Cu plus Cr, Ni and alloyed with Cr, Mn and Cu. The Corten B series is also suitable for European and Japanese weathering steels. It has been widely used. Since the 1960s, China has developed a large number of weathering steels and developed some of its own steel grades, such as Anshan Iron and Steel Group 08CuPVRE series, Wuhan Iron and Steel Group 09CuPTi series, Jinan Iron and Steel 09MnNb, and 10CrMoAl Shanghai Third Steel Plant. 10CrCuSiV etc. Today, weathering steel has been widely used as ordinary steel abroad. It is also covered in detail in Development, use and design of steel grades. Depending on the use, weathering steel can be classified into high structures. Corten steel and weathering steel for welded structures. The former is mainly used for structural components such as vehicles, towers, and buildings. It has excellent atmospheric corrosion resistance and is mainly a Cu-P system, in which the P content is between 0.07% and 0.15%. Therefore, the yield strength of this steel is usually lower than 343MPa, and the thickness of the steel generally does not exceed 16mm. The American ASTM 242 series and the Japanese JAS SPA series weathering steel belong to this category. At present, the development of high weather-resistant steel for this kind of structure in China is very rapid. In addition to imitating several varieties such as 09CuPcrNi (similar to Corten) and 09CuPTi (forked 09MnCuPTi), new varieties with Chinese characteristics have also been developed, such as 09CuPTiRE, 09CuPRE and 08CuPvRE, etc., and national standards have been formulated.