The corrosion resistance of this male 60° seat captive seal product is one of its key characteristics. It is directly related to the service life, sealing effect and overall reliability of the product in different working environments. The corrosion resistance of the product mainly depends on the selection of the sealing surface and the main body material. Usually, manufacturers will choose materials with excellent corrosion resistance and wear resistance, such as stainless steel, alloy steel, etc. These materials have excellent chemical corrosion resistance and can resist the erosion of common media to a certain extent, ensuring that the sealing surface remains stable for a long time and maintains good sealing performance.
Strong acid media, such as hydrochloric acid and sulfuric acid, are extremely corrosive. This type of strong acid will have a strong chemical effect on metal materials, causing chemical reactions on the metal surface and corrosion. For example, hydrochloric acid will undergo a substitution reaction with elements such as iron in the metal to generate metal chloride and hydrogen, which will gradually destroy the metal surface. Sulfuric acid has different ways of corroding metals depending on its concentration. High-concentration sulfuric acid has strong oxidizing properties and can react with many metals.
Ordinary stainless steel valves have no obvious advantage in corrosion resistance over cast iron when facing alkali solution. The corrosion of alkali solution on metal mainly occurs through chemical reaction with oxides or other compounds on the metal surface, destroying the protective layer of the metal and then corroding the metal matrix. For high-temperature alkali solution, the situation is more complicated. High temperature will accelerate the reaction rate of alkali solution and metal, and may cause changes in the internal structure of the metal, reducing the corrosion resistance of the metal.
Most metal valves have limited corrosion resistance in chlorine medium, especially when chlorine is accompanied by water. Chlorine itself has a certain oxidizing property and can react with metal, and the presence of water will accelerate this reaction process. When chlorine is accompanied by water, highly corrosive substances such as hypochlorous acid will be formed, which will cause serious corrosion to metal valves.
Various types of stainless steel valves may show a very low uniform corrosion rate in salt water medium, but the presence of chloride ions may cause local corrosion. Chloride ions have strong penetrability and can destroy the passivation film on the metal surface. A dense oxide film usually forms on the surface of stainless steel to protect the metal matrix, but chloride ions will adsorb on the metal surface and combine with metal ions to form soluble chlorides, thereby destroying the oxide film, exposing the metal matrix to the medium and causing local corrosion.
