Development of hot dip galvanizing
Hot-dip galvanizing was developed from the older hot-dip method. It has a history of 140 years since France applied hot-dip galvanizing to industry in 1836. However, the hot-dip galvanizing industry has developed on a large scale in the past thirty years with the rapid development of cold-rolled strip steel.
Hot dip galvanizing principle
Clean the iron parts, then treat them with solvents, dry them and then immerse them in zinc liquid. The iron and molten zinc react to form an alloyed zinc layer. The process is: degreasing - water washing - pickling - plating - baking Dry - hot dip galvanizing - separation - cooling passivation.
The thickness of the hot-dip galvanized alloy layer mainly depends on the chemical composition such as silicon content of the steel, the cross-sectional area of the steel, the roughness of the steel surface, the temperature of the zinc pot, the zinc immersion time, the cooling speed, cold rolling deformation, etc.
Structural classification code:
Z-normal regular spangle: Spangle obtained by crystallizing at normal cooling rate and can be used for general purposes;
X-minimized spangle: The cooling speed is specially controlled, and the size of the spangle is smaller than that of normal spangle. It is suitable for painting and other occasions where normal spangle cannot meet the requirements; paint and normal spangle cannot meet the requirements. other occasions;
GZ-finished zinc flower: small zinc flower after smoothing treatment, suitable for deep drawing and ultra-deep drawing processing and occasions with low surface roughness requirements.
Zinc layer weight codes: Z100, Z200, Z275; the weight of the galvanized layer refers to the total amount of zinc on both sides of the steel plate, expressed in grams of zinc per square meter of steel plate (g/m2). For example, Z100 means that the zinc content is not Less than 100g/m2.
Uses of hot dip galvanizing
With the discovery of industry, hot-dip galvanizing products have been used in many fields. The advantage of hot-dip galvanizing is that it has long anti-corrosion life and can adapt to a wide range of environments. It has always been a very popular anti-corrosion treatment method. It is widely used in power towers, communication towers, railways, highway protection, street light poles, marine components, building steel structure components, substation ancillary facilities, light industry, etc.
The anti-corrosion life of hot-dip galvanizing is long, but the anti-corrosion life is different in different environments: 13 years in heavy industrial areas, 50 years in the ocean, 104 years in the suburbs, and 30 years in the city.
