A hot-dip galvanizing process

Abstract

The invention discloses a hot-dip galvanizing technology. The hot-dip galvanizing technology comprises the following steps of1 oil removing, specifically, a workpiece is poured into a mixed solution of 10-12g / L sodium carbonate and 12-15g / L sodium hydroxide, and the solution temperature is 90-100 DEG C until the workpiece is completely infiltrated; 2, pickling, specifically, the workpiece is put into a sulfuric acid solution of concentration of 15-20%, pickling is conducted for 5-10min, antifog and corrosion inhibitor is added in the solution, the pickling temperature is 30-50 DEG C, and washing by using clear water is conducted for 2-3 min after pickling is completed; and 3, the workpiece is washed by using warm water with the 50-60 DEG C. The hot-dip galvanizing technology is high in cooling speed of a cooling process, small in water consumption and low in energy consumption, adopts chrome-free passivation, and is environmentally friendly.

Description

Technical field: [0001] The invention relates to the field of galvanizing, in particular to a hot-dip galvanizing process. Background technique: [0002] The hot-dip galvanizing process generally includes the following steps: pickling, cleaning, fluxing, hot-dip galvanizing, cooling and passivation. Among them, acid mist is easily generated during the pickling process, which seriously affects the working environment, and the pickling time cannot be controlled. Appropriate, a large amount of hydrochloric acid will be consumed; the formation process of the hot-dip galvanized layer is the process of forming an iron-zinc alloy between the iron substrate and the outermost pure zinc layer, and the iron-zinc alloy layer is formed on the surface of the workpiece during hot-dip plating, which makes the The combination of iron and pure zinc layer is very good, but zinc dust will be produced in the process, which not only affects the quality of galvanizing, but also affects the product...

AI Technical Summary

Problems solved by technology

[0002] The hot-dip galvanizing process generally includes the following steps: pickling, cleaning, fluxing, hot-dip galvanizing, cooling and passivation. Among them, acid mist is easily generated during the pickling process, which seriously affects the working environment, and the pickling time cannot be controlled. Appropriate, a large amount of hydrochloric acid will be consumed; the formation process of the hot-dip galvanized layer is the process of forming an iron-zinc alloy between the iron substrate and the outermost pure zinc layer, and the iron-zinc alloy layer is formed on the surface of the workpiece during hot-dip plating, which makes the The combination of iron and pure zinc layer is very good, but zinc dust will be produced in the process, which not only affects the quality of galvanizing, but also affects the production efficiency; during the cooling process, the workpiece after hot dipping is at a high temperature of close to 400 ℃, and ordinary In the case of water cooling, the cooling effect is not good. The temperature of the cooling water rises sharply, and the cooling water needs to be replaced in real time. The water consumption is large, and the cooling effect is not good; the last is the passivation process. Severe chromium salt-based hexavalent chromium passivation

Furthermore, the coating of galvanized parts produced by the existing process is uneven and easy to corrode.