What is hot dip galvanized steel pipe

Hot dip galvanized tube is to make molten metal and iron matrix reaction and produce alloy layer, so that the matrix and coating of the combination of the two. Hot dip galvanizing is the first steel pipe pickling, in order to remove iron oxide on the surface of the steel pipe, pickling, through ammonium chloride or zinc chloride aqueous solution or ammonium chloride and zinc chloride mixed aqueous solution tank for cleaning, and then into the hot dip plating tank. Complex physical and chemical reactions occur between hot dip galvanized steel tube and molten plating solution to form a tightly structured zinc-ferroalloy layer with corrosion resistance. The alloy layer is integrated with pure zinc layer and steel tube matrix, so its corrosion resistance is strong. Hot dip galvanized steel pipe with thick zinc layer has the advantages of uniform zinc layer, strong adhesion and long service life.

Hot dip galvanized steel pipe is widely used in fire fighting, construction, machinery, coal mine, chemical industry, electric power, railway vehicles, automobile industry, roads, Bridges, containers, sports facilities, agricultural machinery, petroleum machinery, prospecting machinery, greenhouse construction and other manufacturing industries.

Advantages of hot dip galvanized steel pipe products

Anticorrosion years long, widely adapt to the environment. The anticorrosion life of hot dip galvanizing is long, but the anticorrosion life is different in different environments: 13 years in heavy industrial area, 50 years in ocean, 104 years in suburbs and 30 years in cities. Hot dip galvanizing process: degreasing - water washing - pickling - help plating - drying - hot dip galvanizing - separation - cooling passivation. The thickness of the hot-dip galvanized alloy layer mainly depends on the silicon content of steel and other chemical components, the size of the cross-sectional area of steel, the roughness of the steel surface, zinc pot temperature, zinc immersion time, cooling speed, cold rolling deformation.

1, low processing cost: the cost of hot dip galvanized rust is lower than the cost of other paint coating;

2, durable: in the suburban environment, the standard hot-dip galvanized anti-rust thickness can be maintained for more than 50 years without repair; In urban and offshore areas, the standard hot-dip galvanized coating can be maintained for 20 years without repair.

3, good reliability: galvanized layer and steel is metallurgical combination, become a part of the steel surface, so the durability of the coating is more reliable;

4, the toughness of the coating is strong: galvanized layer forms a special metallurgical structure, this structure can withstand mechanical damage in transport and use;

5, comprehensive protection: each part of the plated parts can be plated with zinc, even in the depression, sharp corners and hidden places can be fully protected;

6, save time and effort: galvanizing process is faster than other coating construction method, and can avoid the time required to brush on the site after installation.

7, the initial cost is low: in general, the cost of hot dip zinc is lower than that of other protective coating, the reason is very simple, other protective coating such as sand paint is labor-intensive process, whereas the process of hot dip zinc is highly mechanized, tightly controlled in the factory construction.

8, simple and convenient inspection: hot dip zinc layer can be visually and simple non-destructive coating thickness table for testing

9. Reliability: The specifications of hot dip zinc are generally implemented in accordance with BS EN ISO 1461, which limits the minimum zinc layer thickness, so its rust protection period and performance are reliable and predictable.

Technological process is: the clarinet, alkaline cleaning, washing, pickling, rinse, leaching agent, drying, hot dip galvanized - - within the outer wind - air cooling, water cooling, passivation, water rinse, inspection, weighing, warehousing.

Influence on elemental properties of hot-dip galvanized steel pipe

•  carbon; The higher the carbon content, the harder the steel, but the less plastic and ductile it is.

•  sulfur; Is harmful debris in steel, steel with higher sulfur in high temperature pressure processing, easy to crack, usually called hot brittleness.

•  Phosphorus; It can significantly reduce the plasticity and toughness of steel, especially at low temperature, which is more serious, and this phenomenon is called cold brittleness. In high quality steel, sulfur and phosphorus should be strictly controlled. But on the other hand, low carbon steel contains higher sulfur and phosphorus, can make its cutting easy to break, to improve the machinability of steel is favorable.

• manganese; Can improve the strength of steel, can weaken and eliminate the adverse effects of sulfur, and can improve the hardenability of steel, high alloy steel with high manganese content (high manganese steel) has good wear resistance and other physical properties.

•  silicon; It can improve the hardness of steel, but the plasticity and toughness decline, electrical steel contains a certain amount of silicon, can improve the soft magnetic properties.

•  tungsten; It can improve the red hardness, thermal strength and wear resistance of steel.

•  Chromium; It can improve the hardenability and wear resistance of steel, improve the corrosion resistance and oxidation resistance of steel.