Galvanizing refers to a surface treatment technology that coats the surface of metal, alloy or other materials with a layer of zinc for aesthetics and rust prevention. The main method used is hot dip galvanizing. Zinc coating is an anodic coating. It is mainly used to prevent corrosion of steel. Its protective performance is closely related to the thickness of the coating. After the zinc coating is passivated, dyed or coated with gloss protectant, its protective and decorative properties can be significantly improved.

Galvanized steel plates are divided into ordinary electrolytic plates and fingerprint-resistant electrolytic plates. The fingerprint-resistant board is based on the ordinary electrolytic board and adds a fingerprint-resistant treatment, which can resist sweat. It is generally used on parts that do not undergo any treatment. The grade is SECC-N. Ordinary electrolytic plates are divided into phosphating plates and passivation plates. Phosphating is more commonly used, and the brand name is SECC-P, commonly known as p material. Passivation plates are available with or without oil.

Hot-dip galvanized steel sheet (SGCC) has one advantage over electro-galvanized steel sheet (SECC). SECC is very easy to rust in bends and sections, while SGCC has much better rust resistance under the same conditions. High-quality chassis usually use SECC or SGCC galvanized steel plates. The chassis steel plates made of this material are bright in color and have a metallic luster. The advantage of this steel plate is that it has good corrosion resistance.

The products of galvanized steel sheet are mainlyused in such industries as construction industrylight industry,automobile industry,agriculture-livestock-fishery industry and commercial industry etc.For construction industry,galvanized steel sheet can be used to produce the anti-corrosive roof panels and roof grille etc.for industrial and civil construction usage.For light industry,producing appliance housings, civil chimneys and kitchenwares etc. For automobile industry, producing anti-corrosive auto parts for cars etc.For agriculture-livestock-fishery industry, producing appliances for storage and transportation of grain, frozen processing appliances for meat and aquatic products and so on.For commercial industry, producing appliances for storage and transportation of goods and materials, packaging appliances and so on.

Cold galvanized

Cold galvanizing is also called electro-galvanizing. It uses electrolysis equipment to degrease, pickle, and then put the pipe fittings into a solution composed of zinc salts, and connects the negative electrode of the electrolysis equipment. Place a zinc plate opposite the pipe fittings and connect it to the electrolytic When the positive pole of the equipment is powered on, a layer of zinc will be deposited on the pipe fittings by using the directional movement of current from the positive pole to the negative pole. Cold-plated pipe fittings are processed first and then galvanized.

Hot dip galvanized

The main method used to galvanize the surface of steel plates is hot dip galvanizing.

The production process of hot-dip galvanized sheets mainly includes: original sheet preparation → pre-plating treatment → hot-dip plating → post-plating treatment → finished product inspection, etc. According to custom, the hot-dip galvanizing process is divided into two categories: off-line annealing and in-line annealing based on different pre-plating treatment methods, namely wet method (single steel plate hot-dip galvanizing method) and off-line annealing (single steel plate hot-dip galvanizing method). Galvanizing method), hot-dip galvanizing Wheeling method (continuous hot-dip galvanizing method for steel strip), in-line annealing Sendzimir method (protective gas method), modified Sendzimir method, American Steel Association method (same as Japan's Kawasaki method), Selas method and Sharon method.

Electro galvanized

1. Principle

Because zinc is not easy to change in dry air, but in humid air, a very dense zinc carbonate film can be formed on the surface, which can effectively protect the interior from corrosion. And when the coating is damaged for some reason and a small base is exposed, the zinc and the steel base form a micro-battery, so that the fastener base becomes the cathode and is protected. It is widely used in automobile transportation and other industries, but what is needed is a trivalent chromium passivation layer and a zinc-nickel alloy plating sealing coating to reduce the harmful and toxic layer of hexavalent chromium passivation.

2. Performance characteristics

The zinc coating is thicker, crystallized finely, uniformly and without pores, and has good corrosion resistance; the zinc layer obtained by electroplating is relatively pure and corrodes slowly in acid, alkali and other mist, and can effectively protect the fastener matrix. The zinc coating is treated with chromic acid After passivation, it forms white, colored, military green, etc., which are beautiful and have certain decorative properties. Since the galvanized layer has good ductility, it can be cold punched, rolled, bent and other forming without damaging the coating.

3. Application scope

The fields involved in electro-galvanizing are becoming more and more extensive. The application of fastener products has spread throughout machinery manufacturing, making galvanized chain link fence, electronics, precision instruments, chemical industry, transportation, aerospace, etc. It is of great significance in the national economy.