Introduction To Hot Dip Galvanizing

The paper

The most widely used iron and steel materials in industry, when used in the atmosphere, sea water, soil and building materials and other environments, will occur varying degrees of corrosion. According to statistics, the world's annual loss of iron and steel materials due to corrosion can account for about 1/3 of its total output. In order to ensure the normal use of steel products, prolong their service life, steel corrosion protection technology has been widely paid attention to.

Hot dip galvanizing is one of the most effective means to delay the environmental corrosion of iron and steel materials. It is to dip the surface of iron and steel products after cleaning and activation in molten zinc solution, and through the reaction and diffusion between iron and zinc, the surface of iron and steel products is coated with zinc alloy coating with good adhesion. Compared with other metal protection methods, hot dip galvanizing technology has incomparable advantages in physical barrier and electrochemical protection of coating, bonding strength of coating and substrate, compactness, durability, maintainability and economy of coating, and adaptability to shape and size of products. At present, hot dip galvanized products mainly include steel plate, steel belt, steel wire, steel pipe, etc., among which hot dip galvanized steel plate accounts for the largest proportion. For a long time, hot dip galvanizing process has been favored by people because of its low plating cost, excellent protection characteristics and beautiful appearance. It is widely used in automobile, construction, household appliances, chemical, machinery, petroleum, metallurgy, light industry, transportation, electric power, aviation and Marine engineering and other fields.

Introduction of the process

The principle of hot dip galvanizing, in simple terms, is to clean the clean iron parts, through the wetting effect of the plating agent, immersed in the zinc bath, so that iron and steel and molten zinc reaction to generate an alloyed skin film. A good hot dip galvanizing operation should ensure that all processes are under strict control and give full play to the function of the process. And if the operation of the previous process is not good, it will cause a chain of adverse reactions in the subsequent process, and greatly increase the operation cost or cause bad hot dip galvanized products. If the pretreatment is not good, the molten zinc can not react with steel normally and completely, forming the most perfect galvanized skin film tissue. If the post-treatment is not good, it will destroy the appearance of galvanized skin film and reduce the value of goods.