热镀锌资料（Hot-dip galvanizing data）.docVIP

热镀锌资料（Hot-dip galvanizing data） Hot-dip galvanizing 1. Hot dip galvanizing of steel surface is the reaction and diffusion process between solid metal and liquid metal. 2. The thickness of the diffusion layer depends mainly on the diffusion time at a given temperature and can be expressed by the lower form: Y2 = 2pt 3. At a given temperature, the thickness of the diffusion layer will increase according to the parabolic time of the diffusion time. 4. Through the study of iron zinc reaction, it has been proved that there are two basic processes in the formation of zinc coating alloy layer. First, iron is dissolved in zinc; second, metal compound is formed. 5, hot galvanizing, the iron atoms ran into the liquid zinc, forming a certain concentration of solution. If the concentration of this solution is below the saturation concentration of the temperature (the galvanizing time is short), no solid phase is produced during the reaction. 6. Under the given hot galvanizing condition, the thickness and structure of the alloy layer depend mainly on the relation between the dissolution rate of iron and the speed of the formation of the metal compound. 7 and gamma, which is the intermediate metal phase based on compound Fe5Zn21; 8, delta 1 phase, it is based on FeZn7 intermediate metal phase; 9, it is in the middle of the zeta phase, metal FeZn 13 based; 10, ETA phase, which is composed of pure zinc containing trace iron (0.003%) solid solution. 11, in the galvanizing temperature for the formation of gamma and delta zeta, ETA 1, equal to 4 layers may only 470 C within the range of 450. 12, gamma phase, the zeta phase is brittle phase. 13, 8 1, ETA phase are plastic phase. 14, the outer layer of pure zinc layer, its formation depends only on the thickness of the gas jet pressure and the speed of the strip and other factors, it is the best extension of the layer. 15, the increase of temperature can accelerate the diffusion speed between Fe and Zn, and it can be determined that the