Introduction
Corrosion is a common problem in the metal industry that causes economic losses, threatens the safety of personnel and infrastructure and causes pollution of the environment. Corrosion prevention and control technology is a common technology and knowledge needed in the production of metal industry.
Definition and Classification
Corrosion is a chemical or electrochemical process that degrades the material and destroys its surface, resulting in various forms of damage. Corrosion prevention and control technology is a technology and knowledge used to reduce the corrosion rate of metal materials and prevent metal materials from being corroded. According to the protection range of anti-corrosion technology, it can be classified into the following four categories:
(1) Surface protection technology: This refers to the coatings and surface treatments used to protect metal materials. This is the most commonly used form of corrosion protection and can be further divided into coatings, surface treatments, and surface passivation technologies.
(2) Cathodic protection technology: This refers to the deliberate use of electrical currents that prevent corrosion by counteracting the current generated by corrosion.
(3) Injection protection technology: This refers to the use of special liquid or powder filler materials to fill the porous side space of the metal material, which can change the chemical environment of the material surface and prevent chemical corrosion.
(4) Control of the chemical environment: The so-called control of the chemical environment refers to the prevention of corrosion by controlling the PH value, oxygen content, and chloride content in the atmosphere or working fluid.
Common Anti-corrosion Methods
The following are some common anti-corrosion methods used in the metal industry:
(1) Protective coating: Protective coating is the most common way to prevent corrosion. According to the methods of application, it can be divided into inner coating, spray coating, electroplating, thermal spray coating and so on.
(2) Anodizing: An anodizing process is mainly used to prevent aluminum from corrosion. It is a process of forming an oxide film on the surface of the substrate by anodization under the action of electric current.
(3) Grease and oil coating: A protective coating composed of grease and oil can also be used to prevent corrosion of metal materials. This protective coating has good water resistance and sealing properties and does not cause environmental pollution.
(4) Passivation: Passivation is a method that uses chemicals such as nitrlates, phosphates and chromates to treat the surface of metal materials to form a compact and dense oxide film, making the material surface resistant to corrosion.
(5) Galvanizing: Galvanizing is a process in which metal substrates are coated with a layer of zinc to protect them from corrosion.
Conclusion
Corrosion prevention and control technology is an important technical field for the production of metal industry, and its application plays an important role in reducing economic losses, improving personnel and infrastructure safety, and reducing environmental pollution. These common anti-corrosion methods mentioned above are widely used in the field of metal production, and play an active role in the improvement of product quality and production efficiency.
