Steel structures have a wide range of applications in many industries, such as construction, petrochemical, shipbuilding, etc. However, steel structures are also facing the problem of corrosion, which will not only affect their service life, but also pose a threat to the safety of people's lives and property. Therefore, anti-corrosion is a very important issue in the field of steel structures. This article will discuss the necessity, corrosion mechanism and anti-corrosion method of steel structure from three aspects, so as to help readers better understand the actual situation in this field.
First, the necessity of anti-corrosion of steel structures.
Steel structures have a wide range of applications in many industries, such as construction, petrochemical, shipbuilding, etc. However, due to the long-term exposure of the steel structure in the natural environment, affected by natural factors such as wind and rain, sun and night dew, its surface is prone to corrosion. Corrosion will not only reduce the bearing capacity and service life of the steel structure, but also pose a threat to the safety of people's lives and property. Therefore, anti-corrosion is a very important issue in the field of steel structures.
2. Corrosion mechanism.
The corrosion mechanism of steel structures can be divided into two types: chemical corrosion and electrochemical corrosion. Chemical corrosion is corrosion caused by a chemical reaction between the surface of a steel structure and the surrounding medium. For example, in a dry environment, when steel comes into contact with oxygen, water vapor and other media, an oxidation reaction will occur, resulting in the formation of iron oxide and other compounds, resulting in the destruction of the steel surface. Galvanic corrosion is caused by the formation of galvanic cells due to the contact between the surface of the steel structure and the electrolyte solution, which is caused by the action of electric current. For example, in a humid environment, when steel comes into contact with an electrolyte solution, an electrochemical reaction occurs, resulting in the destruction of the steel surface.
3. Anti-corrosion methods.
In order to prevent corrosion of steel structures, the following methods can be adopted:
1.Anti-rust treatment.
Anti-rust treatment is the first step in anti-corrosion. Commonly used anti-rust treatment methods include anti-rust paint, galvanizing, spraying, etc. These methods can form a protective film on the surface of the steel structure to prevent moisture, oxygen and other media from coming into contact with the steel, so as to achieve the purpose of rust prevention.
2.Paint protection.
Coating protection refers to applying a layer of paint or coating to the surface of a steel structure to form a protective film to prevent the corrosive medium from coming into contact with the steel. Commonly used paints and coatings are epoxy resins, polyurethanes, acrylic resins, etc. Coating protection can not only play a role in rust prevention, but also increase the decorative effect of the steel structure.
3.Cathodic protection.
Cathodic protection is a method of preventing galvanic corrosion by changing the potential of a steel structure. Commonly used cathodic protection methods are impressed current method and sacrificial anode method. The impressed current method is to change the potential of the steel structure by impressing an electric current to make it a cathode and be protected. The sacrificial anode method is to connect metals that are more reactive than steel (such as zinc, magnesium, etc.) to steel, so that the steel becomes a cathode and is protected.
4.Hot-dip galvanized.
Hot-dip galvanizing is to immerse steel in a molten zinc bath to form a dense zinc layer on the surface of steel, so as to achieve the purpose of anti-corrosion. Hot-dip galvanizing has the advantages of good corrosion resistance, long life and low cost, so it has been widely used in many fields.
5.FRP anti-corrosion layer.
FRP is a composite material composed of glass fiber and organic polymer materials, which has the advantages of good corrosion resistance, high strength and long life. Coated with a layer of FRP on the surface of the steel structure can play a good role in anti-corrosion. However, the construction process of FRP is more complex and requires professional operators to operate.
To sum up, anti-corrosion is a very important issue in the field of steel structure. In order to prevent corrosion of steel structures, a variety of anti-corrosion methods can be employed. In practical application, the appropriate anti-corrosion method should be selected according to the specific situation to ensure the service life and safety of the steel structure.