Coating methods in anticorrosion engineering mainly include

Basic knowledge of anticorrosion technology commonly used in engineering (1) Coatings can be divided into two categories: oily coatings (film-forming substance is drying oil) and resin-based coatings (film-forming substance is synthetic resin). The corrosion resistance of coatings refers to the corrosion resistance of paint films. 1 Basic composition of coatings Although there are many kinds of coatings, their composition can be roughly divided into three parts, namely, main film-forming substances, secondary film-forming substances and auxiliary film-forming substances. (1) Main film-forming substances. L) oil. 2) Natural resin and synthetic resin. (2) Secondary membrane substances (pigments). Pigment is one of the main components of coatings. Adding human pigment into the paint can not only make the paint decorative, but also improve the physical and chemical properties of the paint, improve the mechanical strength, adhesion, impermeability and corrosion resistance of the paint, and filter out harmful light waves, thus improving the weather resistance and protection of the paint. 2. Coating methods mainly include the following coating methods: (1) brush coating method. (2) spraying method. Spraying methods are generally divided into high-pressure airless spraying and electrostatic spraying. High-pressure airless spraying method is suitable for large-area construction and spraying high-viscosity coatings. (3) Dip coating method. Generally, it is not suitable for coatings that dry quickly. (4) Electrophoretic coating method. Electrophoretic coating is a new coating method, which is suitable for waterborne coatings. 3. Ordinary paints, antirust paints and primers can be divided into primer and topcoat according to their functions. (1) Raw lacquer (also called lacquerware). Raw lacquer is a taupe viscous liquid, which has the advantages of acid resistance, solvent resistance, water resistance, oil resistance, wear resistance and strong adhesion. The disadvantage is that it is not resistant to strong alkali and strong oxidant. Raw lacquer is also resistant to soil corrosion and is a good coating for underground pipelines. (2) Urushiol resin paint. It changes the disadvantages of raw lacquer, such as high toxicity, slow drying and inconvenient construction, but still maintains other advantages of raw lacquer, and is suitable for large-scale rapid construction. Urushiol resin paint can be sprayed or brushed, which is generally used. For pipes with smaller diameter, when painting is difficult, pouring method can be used for construction. If the painted components are small, the impregnation method can be used for construction. (3) phenolic resin paint. Resistant to 60% sulfuric acid, hydrochloric acid, acetic acid and phosphoric acid with a certain concentration, most salts and organic solvents. However, it is not resistant to strong oxidants and alkali, the paint film is fragile, and it is easy to crack when the temperature difference changes greatly, and its adhesion to metals is poor, so its application in production is limited. The coating method includes brush coating, spray coating, dip coating and casting. (4) Epoxy phenolic paint. (5) Epoxy resin coating. Epoxy resin coating has good corrosion resistance, especially alkali resistance and good wear resistance. Excellent adhesion to metals and nonmetals (except polyethylene and polyethylene). (6) * * vinyl paint. It has good industrial atmosphere resistance, seawater resistance, acid resistance, oil resistance, salt spray resistance, mildew resistance and flame retardancy. But it is not resistant to the corrosion of organic solvents such as phenols, * * *, lipids and benzene. Its maximum service temperature is about 70℃. Varnish is not light resistant, easy to age, and has weak adhesion to metal surfaces, especially smooth surfaces and non-ferrous metal surfaces. (7) Asphalt paint. It can resist the corrosion of nitrogen oxides, sulfur dioxide, sulfur trioxide, ammonia, acid mist, gas, low-concentration inorganic salt, alkali, seawater, soil, salt solution and acid gas with concentration below 40% at room temperature. But it is not resistant to corrosion by organic solvents such as oil, alcohol, lipid, hydrocarbon and strong oxidant. Commonly used asphalt paints include asphalt acid-resistant paint, asphalt varnish and aluminum powder asphalt antirust paint. Asphalt coating construction generally adopts brush coating method, and rarely adopts spraying method. (8) Furan resin paint. Bark resin paint can only be cured under the action of acid curing agent and heating. However, the acid curing agent has an acid corrosive effect on metal (or concrete), so it is not suitable to be directly coated on the surface of metal or concrete, and other coatings must be used as the primer. (9) Polyurethane paint. (l0) Inorganic zinc-rich paint. Suitable for seawater, clean water, marine atmosphere, industrial atmosphere and oil. 4. Plastic Coatings Plastic coatings mainly include polyethylene coatings, poly * * * ethylene coatings, * * * polyether coatings, poly * * * * ethylene coatings and * * *-46 coatings. The construction methods of polyethylene coating include flame spraying, fluidized bed spraying and electrostatic spraying. 5, coating naming principle full name = pigment or color name 100% membrane material name 10 basic name coating model