What is the function of hot-dip galvanized channel steel plating aid？

The role of plating aid for hot-dip galvanized channel steel. The so-called assisted plating is the process of dipping the parts after pickling into a certain component of zinc ammonium chloride coplating solution, and forming a thin zinc ammonium chloride film on the surface of the remanufactured parts.

The role of plating aid

1) Play a cleaning role on the surface of the steel, remove the residual iron salt or oxide on the surface of the refabricated parts after the hydrochloric acid washing, so that the surface activity of the steel parts is maximum when they enter the zinc bath.

2) A layer of salt film is deposited on the surface of the refabricated part, which can prevent the rust in the air during the period from the plating aid pool to the zinc pan.

3) Purify the liquid phase zinc in the zinc bath of the parts, so that the parts and the liquid phase zinc quickly infiltrate and reflect.

Activation of a surface covered zinc chloride ammonium salt film

1】 Below 200℃, a compound hydrochloric acid will be formed on the surface of the parts, approximately in the form of H2[Zn2CL2], which is a strong acid, so as to ensure that the surface can not form an oxide film during the redrying process and maintain an active state.

2】 Above 200℃, the NH4CL in the salt film of the surface coplating solution will decompose into NH3 and HCL at a higher temperature, at which time the erosion of HCL on the steel matrix is dominant, so that the surface of the steel matrix cannot form oxides and maintain the activation of the steel matrix. Therefore, the correct use of plating AIDS containing NH4CL in hot dip galvanizing is very heavy.

Tell about some concepts of corrosion prevention of hot galvanizing equipment, and now let's tell you about some detailed processes of hot galvanizing equipment in galvanizing, so that you can objectively understand some detailed processes of products in hot galvanizing, and you can intuitively understand how to avoid product oxidation if the product is anticorrosive and in daily life.

Consumption process of hot-dip galvanizing equipment in galvanizing (galvanized flow chart of hot-dip galvanizing equipment) Consumption process of hot-dip galvanizing (steel pipe) : feeding → pickling, washing → solvent → drying → hot-dip galvanizing → internal and external blowing → rolling mark, marking → passivation → inspection → packaging. The feeder should check the condition of raw materials: the surface of the steel pipe should not be adhered to oil (especially asphalt oil mixing paint and other oil), otherwise a large number of unqualified products will be formed.

The pipe must be straightened after consumption to eliminate the internal stress of the steel pipe. The surface of the steel pipe shows uneven corrosion can not be galvanized, otherwise it will waste a lot of hydrochloric acid. The pipe must not be artificially bent during transportation. For the steel pipe used for hot dip galvanizing, it is not allowed to stick the marker on the inner and outer walls of the steel pipe to avoid the formation of leakage plating.

Hot-dip galvanized pickling, water washing, and pickling of steel pipes: pickling workers must wear labor maintenance supplies before work, carefully check whether the work site is barrier-free and whether the sling is intact during work, and confirm that the work can be stopped in front of good condition. Hydrochloric acid pickling is mainly used, and hydrochloric acid is prepared with water, and the content of hydrochloric acid is 18~20%.