High temperature closed coatings effectively prevent decarbonization and oxidation in steel quenching

China Coatings Online News:
the process of reducing or removing carbon content due to oxidation or reaction to surrounding media during steelmaking or heat treatment. When steel is heated, the surface carbon reacts with oxygen, hydrogen, carbon dioxide and water vapor in the medium (or atmosphere), reducing the surface carbon concentration called decarbonization, reducing surface hardness, fatigue strength and wear resistance after quenching of decarbonization steel, and forming residual pull stresses on the surface to easily form surface mesh cracks. The result is that the steel does not meet the requirements. High temperature closed coating experts suggest that this phenomenon should be avoided in heat treatment processing. High temperature oxidation atmosphere metal protection closed coating to prevent corrosion oxidation, numerous experiments and steel factory after the field use proved that in high temperature conditions, the coating intact, steel plate area of more than 95% non-oxidation phenomenon, the overall effect is very ideal. High temperature-resistant closed oxidation coating for metal heat treatment, can effectively shield the air of oxygen and other corrosive media penetration, so that steel in a non-contact with corrosive media in the environment of heating, can avoid the oxidation loss of steel in heat treatment, reduce the removal of oxidation skin process, and make the specification size of the work piece more accurate It can avoid the reduction of metal fatigue intensity due to decarbonization during heat treatment and prolong the service life of steel, and the ZS-1021 high temperature closed oxidation coating can prevent the metal from absorbing gas on the surface during heat treatment, prevent the metal from being brittle due to oxygen absorption, and enhance the corrosion resistance after metal heat treatment.
oxide skin is a dense layer of oxidation produced by steel at high temperature forging and forming, which is usually attached firmly, but has less flexibility and extendability than steel. From electrochemical analysis, the electrode level of oxidizing skin is 0.15-0.20V higher than iron, so high temperature anti-oxidation decarbonization coating researchers specifically proposed that in the corrosion medium, iron before oxidation skin corrosion, especially in the presence of a large number of oxidizing skin, a large number of oxidizing skin for the cathode, a small amount of exposed iron becomes a small anode, will accelerate the promotion of local corrosion of iron. In wet environments, large cathodes formed by oxidizing skins and small anodes formed by exposed steel can exacerbate local corrosion of steel in exposed areas. There are numerous small gaps between the skin and steel surface, and the penetration of water and corrosion media into the loose skin of oxidation can cause gap corrosion and deep corrosion.
High temperature closed coating effectively prevents decarbonization and oxidation in steel quenching
various corrosive media make steel oxidized and decarbonized at high temperature, resulting in huge loss of material and decline in the performance of the material, so steel in high temperature treatment needs certain protective measures to reduce high temperature oxidation measures are: vacuum protection heating, controlled atmosphere protection, coating protection, etc., of which coating protection is a very economical and effective method. Coatings company for the industrial steel high temperature oxidation problem to develop a high temperature antioxidant coating high temperature closed coating, temperature resistance up to 2300 degrees C. The core technology of the coating is the film-forming substance used in the coating, using silicate-modified solution to form an organic-inorganic hybridized high-concentration film. At high temperatures, it has a very significant effect of reducing the oxide skin of steel surface, because it combines three nanomaterials with the most characteristic characteristics of high temperature protection: boron oxide, silicone and alumina, respectively, with reaction protection, film shield protection and oxidation prototype protection three different protection concepts. At about 600 degrees C, a dissolved boron oxide film can be formed, and a dense and firm inorganic silicate ceramic film layer is formed at about 700 degrees C, which isolates the contact between air and steel surfaces, thus acting as a protective effect, while aluminum powder in coatings is oxidized at high temperatures and is resistant to high temperature closure. The oxidizing coating forms a dense layer of alumina with a very high melting point (melting point of about 2050 degrees C) In this redox reaction process, due to the large reaction of active gases such as aluminum and oxygen near the surface of steel, a vacuum area of the active gas is formed, thus protecting the steel surface from corrosion oxidation and decarbonization.