A Metal Passivation Process Combining Oxygen Addition and Cathodic Protection

Abstract

The invention discloses a metal passivation technology with combined oxygenation and cathode protection, belongs to the technical field of metal surface chemical treatment, and particularly relates toa metal passivation technology. According to the metal passivation technology with combined oxygenation and cathode protection, spontaneous passivation occurs to cleaning equipment metal in water with the pH ranging from 9.3 to 10 by using oxygen of high concentration so as to form good oxidized protective film with ferric oxide as the main ingredient, and the metal passivation efficiency and quality are improved at the same time. The usage amount of strong oxidizers and the usage amount of reducing agents are greatly reduced, the cost payout is reduced, and meanwhile the waste liquid amountof chemicals is reduced as well, and the handling expense for the part of chemical waste water is omitted. Because the oxygen in the air is adopted, the raw material is easy to obtain, and the cost islow. The oxidized passivation film mainly comprises the top-valence oxides of iron, chrome and the like, the film is complete, dense, and uniform in gap, is the smallest in expansion difference frommetal relatively, and is lowest in solubility, and the durability of the protective film can be benefited.

Description

technical field [0001] The invention belongs to the technical field of metal surface chemical treatment, and in particular relates to a metal passivation process. Background technique [0002] The lower the energy (potential energy) of the substance itself, the more stable its form, and the less likely it is to participate in chemical reactions or transformations. Compared with high-energy substances, low-energy substances have much lower energy (potential energy), so the reaction of low-energy substances The activity is low, when the energy (potential energy) of any substance is at the lowest position, the form of the substance is in the most stable state. [0003] Metal ions are a form in which the metal energy (potential energy) is at the lowest level. Therefore, metals exist in the form of ions in nature. In order to make the metal have usability and processing performance, artificially adopt smelting, refining and other technical means to make the metal Ore in its ioni...

AI Technical Summary

Problems solved by technology

At present, the main methods of passivation after cleaning are: passivation of strong oxidizing substances and passivation of reducing agents. Both of these methods require chemicals, which not only increase the cost of cleaning, but also generate a large amount of chemical waste. The treatment of chemical waste liquid is becoming more and more strict, and the disposal cost accounts for about 1 / 3 of the chemical cleaning cost