Hot Dipped Galvanized Steel Coil

OVERVIEW OF HOT DIPPED GALVANIZED STEEL COIL

Hot-dip galvanizing refers to the process of applying a protective zinc coating to a steel sheet or iron sheet, in order to prevent rusting. As the full hard steel has undergone acid washing followed by a rolling process through the zinc pot, a layer of zinc film is applied to the sheet’s surface. Henceforth, hot dipped galvanized steel sheet in coil (GI) is produced. High quality hot dipped galvanized steel coil with reasonable price is a popular steel product with high level of corrosion resistance, paintability, and workability. It is frequently used in a broad spectrum of industries and sectors. As China galvanized steel coil suppliers, Cumic is determined to supply highly cost effective galvanized steel coil in China. Meanwhile, Cumic could give customers reasonable hot dipped galvanized steel coil price.

PARAMETER OF HOT DIPPED GALVANIZED STEEL COIL

APPLICATION OF CHINA GALVANIZED STEEL COIL

Applications in the steel structure industry

Hot rolled galvanized is mainly used in the steel structure industry for light steel houses and plants, whose main building skeleton are made of galvanized cold-formed steel, mainly C-beams, Z-beams, floor bearing plates and steel guttering, with thickness specifications of mainly 1.5-3.5mm. Because of the light weight, high strength, beautiful shape, fast construction, less pollution, good wind and earthquake resistance of steel buildings, China galvanized steel coil is an environmentally friendly “green building materials”.

Applications in the railroad coach manufacturing industry

The outer shell, inner shell and top and bottom plates of passenger carriages are manufactured using 1.0-3.0mm galvanized steel sheet china. Hot-rolled galvanized sheet replaces cold-rolled sheet, simplifying the process, speeding up the manufacturing cycle and extending the service life of the vehicle. The average amount of hot-rolled galvanized sheet used per bus is 15 tons, including 4.5 tons for 1-2.75mm. The national annual bus manufacturing capacity is about 10,000 units, and it is estimated that about 45,000 tons of hot-rolled galvanized sheet are needed.

Applications in the automotive industry

The amount of coated steel plates for automobiles in developed countries has accounted for more than 60% of the amount of thin plates, and the automobile industry in China has been developing rapidly in recent years. It is an inevitable trend to widely use galvanized sheets as auto body coverings to improve corrosion resistance. From the automotive use of galvanized sheet, its use specifications are more, the dosage is relatively large, mainly used in the bottom plate of the car, various beams, beam reinforcement plate, support, bracket and connection plate. As it is used in hidden parts, it does not require high surface quality and deep punching performance, thus some parts can be processed with hot substrate galvanized sheet instead. The specification of hot galvanized sheet for automotive consumption is mainly 1.5-3.0mm.

PRODUCTS DEVELOPMENT OF GALVANISED STEEL COIL

With the development of hot-rolled technology, the quality of galvanised steel coil products has been improving and the thickness has been gradually decreased. The use of hot-rolled sheet as raw material to produce hot-rolled galvanized sheet has replaced the traditional sheet galvanization, which has not only broadened the use of hot-rolled galvanized sheet, but also crowded out the market share of hot-rolled galvanized sheet with cold-rolled sheet as the substrate. Internationally, hot-rolled galvanized sheets have been widely adopted.

With the progress of hot rolling technology, especially the maturity of thin slab casting and rolling (CSP) technology, the thickness of hot-rolled steel strip is becoming thinner and thinner. In recent years, the country has built a number of CSP production lines. The design of the thinnest rolling specifications up to 0.8mm. CSP technology is used in large numbers, objectively for the hot-rolled galvanized plate to provide better mechanical properties and specifications of thinner hot-rolled raw materials.

PROCESS INTRODUCTION TO HOT DIPPED GALVANIZED STEEL COILS

The principle of hot dipped galvanizing is simply that a cleaned iron part is dipped into a zinc bath through the wetting action of a plating aid, and the steel reacts with the molten zinc to form an alloyed film. A good hot dip galvanizing operation is one in which all processes are under strict control and the functions of the process are thoroughly performed. Poor operation of the previous process can result in a chain of adverse reactions in the subsequent processes, which can significantly increase operating costs or result in poor hot dipped galvanized steel coils. If the pre-treatment is poor, the molten zinc will not react with the steel to form the most perfect galvanized film. If the post-treatment is poor, the appearance of the galvanized film will be damaged and the value of the product will be reduced.

ADVANTAGES OF CHINA GALVANIZED STEEL SHEET

1. The entire steel surface is protected, and the dissolved zinc is easily and evenly covered, whether inside the recessed fittings or in any other corner where the coating is difficult to access.

2. The hardness value of the galvanized layer is greater than that of the steel. The top layer, Eta layer, is only 70 DPN hardness, so it is easily dented by collision, but the lower layers, Zeta layer and delta layer, have 179 and 211 DPN hardness values respectively, which are higher than the 159 DPN hardness value of iron, so its impact and abrasion resistance are quite good.

3. In the corner area, the zinc layer is often thicker than other areas, and has good toughness and anti-abrasion properties. Other coatings in the corners are often the thinnest and most difficult to construct and are most likely to be injured, so maintenance is often required.

4. The consumption of zinc in the atmosphere is very slow, about 1/17th to 1/18th of the corrosion rate of steel, and is predictable. Its life expectancy far exceeds that of any other coating.