A. When the thickness of the plating is 3-4 mm, the zinc adhesion should be less than 460g/m, that is, the average thickness of the zinc layer is not less than 65 microns.
Environmental factors should be considered when choosing the thickness of galvanized layer. Galvanized wire in galvanized, pay attention to the above problems, can be well galvanized, to ensure the quality of galvanized wire. Galvanized methods are mainly divided into two types, one is hot dip galvanizing method, the other is electric galvanizing method. This paper mainly introduces the method of galvanizing. Electrogalvanizing is an electrolyte used for galvanizing.
In reinforced concrete structure, the crack width of cold wire drawing is smaller than that of circular steel bar or even that of hot rolled thread bar. So cold wire drawing is more popular in the construction industry. The material for cold drawing is made of steel bars and can be simply explained how it is made, that is, its production process is simple. It’s based on steel bars, which are constantly stretched evenly, stretching the bars into something very thin, like wire drawing, without plasticity.
Annealing wire is widely used mainly because it has a good elasticity and flexibility, in the annealing process can be a good control of its hardness and softness, it is mainly made of iron wire, more commonly used in the construction industry tie wire use. When the wire factory is in production, the annealing wire will be processed according to the performance of the material, and its hardness will be changed according to the different demand, which can make it have more advantages, reduce the consumption of metal and reduce the cost of production.
Electric galvanized wire is dipped in the zinc solution of heating ablation, the production speed is fast, the coating is thick but not uniform, the market allows a low thickness of 45 microns, up to 300 microns or more. The color is dark, the zinc metal is consumed, and the matrix metal is formed into the entry layer, the corrosion resistance is good, and the outdoor environment of hot dip galvanized can adhere to decades.
In order to remove defects such as surface film layer and surface inclusion of large roll galvanized wire, it can be treated by conventional technology. The presence of small homogeneous particles of large denier in the tank can stabilize the foam layer, but the accumulation of too many solid particles can cause explosion. Activated carbon mat to remove surface active substances, or through filtration to make the foam less stable, these are effective measures; Other measures should also be taken to minimize the intake of surface active substances. The electroplating speed can be significantly reduced by the introduction of organic matter.
“Dry” hot dip galvanizing is also called “drying solvent method” hot dip galvanizing. Iron and steel work pieces through degreasing, pickling, cleaning, dipping aid solvent and drying, and then immersed in the molten zinc solution to galvanize. The co-solvent is usually hydrochloric acid, ammonium chloride, or ammonium chloride mixed with zinc chloride in aqueous solution.
Paint on the galvanized layer, the bonding force between each other has a great relationship with the baking temperature of the paint, and alkyd paint is coated after galvanized, and the adhesion is not a problem. After galvanized to do amino paint, paint adhesion is not very good. Do two bottom two surface, adhesion is good, if the two bottom two surface changed to two bottom three surface, that is, more paint, more baked once, again test adhesion is very bad, bad enough to tear the paint from the galvanized layer.
Poor pretreatment before plating; Bath temperature is too low; Poor quality of additives or too many additives and organic impurities will cause poor bonding. The quality of additives also has an effect on coating foaming. Some additives react incompletely during synthesis and continue to polymerize during long-term storage or use. The additive tends to distort the crystal lattice and cause stress, causing the coating to bubble.
5, the concentration of plating aid can not be too high, which is a factor that can not be ignored to reduce zinc consumption. The concentration of plating aid should not be too high. The galvanized line must be added with ammonium chloride and zinc chloride according to the data of laboratory analysis, and the specific gravity of the composite solution should be controlled within the range of 50~80g/L. If ammonium chloride or zinc chloride is arbitrarily added without the results of laboratory analysis, it should be criticized and educated, and economic treatment should be given if necessary.
Iron and steel in the condition of cooling on the surface galvanized, and hot dip galvanized steel pipe in the condition of hot dip on the surface, its adhesion is strong, not easy to fall off, hot dip galvanized pipe although also rust phenomenon, but in a long period can meet the technical and sanitary requirements.
Compared with galvanizing, hot-dip galvanizing has lower production cost and less environmental impact than galvanizing. Because the coating obtained is thicker, hot-dip galvanizing has better protective performance than electric galvanizing, so it is an important protective coating for steel parts used in harsh working environment. Hot-dip galvanized products are widely used in chemical equipment, petroleum processing, ocean exploration, metal structure, electric power transmission, shipbuilding and other industries.
The spring steel wire is made of high carbon and high quality carbon structural steel or carbon tool steel wire rod, and its chemical composition, gas content and non-metallic inclusion must be strictly controlled according to the use of the spring. In order to reduce the appearance of shortcomings and decarbonization layer, the consumption of rod billet to stop surface grinding, if necessary, but also stop peeling.