Stainless Steel Electrolysis and passivation synergistic process is a technical means to effectively improve the corrosion resistance of stainless steel, and there is a complex and sophisticated enhancement mechanism behind it.
First, during the electrolysis process, an electrochemical reaction occurs on the surface of stainless steel. Anodic electrolysis causes the microscopic protrusions on the surface of stainless steel to dissolve preferentially, thereby flattening the surface and reducing the possibility of accumulation of dirt, impurities and the formation of corrosion micro-batteries on the surface. For example, at the microscopic level, electrolysis removes scratches, mechanical damage and other defective parts generated during the processing of stainless steel, which are originally very easy to become corrosion starting points. At the same time, a thin oxide film will be formed during the electrolysis process. Although this oxide film is relatively loose, it lays the foundation for the subsequent passivation treatment. It can hinder the direct contact between the corrosive medium and the stainless steel matrix to a certain extent, and initially improve the corrosion resistance.
Next, the passivation treatment stage is the key link. The oxidant (such as nitric acid) in the passivation solution reacts with the metal atoms on the surface of the stainless steel, prompting the formation of a dense and stable passivation film on the surface. This passivation film is mainly composed of chromium oxides, hydroxides, etc., which have extremely low solubility and extremely high chemical stability. During the passivation process, the initial oxide film formed by electrolysis merges and complements the passivation film, making the passivation film more uniform, continuous and of appropriate thickness. For example, on the surface of some stainless steel products with complex shapes, the synergistic process can ensure that a good passivation film is formed in all parts to avoid corrosion hazards caused by insufficient local passivation.
Furthermore, from an electrochemical point of view, the presence of the passivation film changes the electrode potential on the surface of the stainless steel, causing it to enter the passivation zone, greatly reducing the electrochemical activity of the stainless steel. When corrosive ions (such as chloride ions, etc.) approach the surface of stainless steel, the passivation film will hinder the migration and adsorption of ions and inhibit the occurrence of electrochemical reactions, thereby effectively preventing local corrosion phenomena such as pitting and crevice corrosion of stainless steel. Moreover, when the passivation film formed by the synergistic process is subjected to a certain degree of mechanical damage or local damage, due to its good combination with the substrate and the protective effect of the surrounding complete passivation film, it can self-repair under certain conditions and restore its protective ability to the stainless steel substrate.
The Stainless Steel Electrolysis and Passivation Collaborative Process significantly enhances the corrosion resistance of stainless steel through multiple mechanisms such as surface flattening by electrolysis, initial oxidation and passivation to form a dense and stable film layer, changing the electrochemical properties and imparting self-repairing ability. This allows stainless steel to maintain good performance for a long time in harsher corrosive environments and is widely used in chemical industry, marine engineering, food processing and many other fields with high requirements for corrosion resistance.
