Common problems and faults in electroplating and galvanizing

Common problems and solutions in electroplating and galvanizing, and how many types of electroplating and galvanizing are common: If this article is helpful to you, please read on. The solution is formulated because the water quality hardness is too high. You can get the right beige coating by using 4m1/l of "stainless steel" target=plant>stainless steel pickling and passivation solution "produced by Zhejiang Huangyan Fluorescent Chemical Plant.

The pre-treatment process is: chemical degreasing powder → hot water washing → cold water washing → acid washing and rust prevention water rust removal → 2 times of active water washing → electric oil elimination → hot water washing → flowing water washing → pre plating activation → 2 times of active water washing → galvanizing. Electrolysis for several hours, stir the solution slightly, and plate in a few tanks. The newly prepared zincate bath solution was prepared cruelly according to the process requirements, and the example of impurity purification method was not forgotten, but the initial overall plating was not good. If it is triggered by impurities of heavy metals, add 1-3 g/l of zinc powder or use the alkaline zinc plating impurity treatment agent CK-7780.5g/l produced by Kaifeng Electroplating Chemical Plant to enrich and stir the plating solution and filter it. Then, add 2-4g tartaric acid or 1g disodium EDTA per liter of plating solution to further mask metal impurities, resulting in a brilliant beige coating. This is due to the stratification of Zn2+concentration in the newly prepared tank solution. The concentration of Zn2+in the lower layer of the plating solution is high, while the concentration in the upper layer is low. (Chemical differentiation should take the uniform values of top, middle, and bottom). At the same time, during normal anodic ablation, the current at the lower end of the anode is high, and there is a current of Zn2+present. Due to the high proportion of Zn2+, the melted Zn2+on the anode sinks downwards, resulting in uneven high and low concentrations of Zn2+.

The degreasing powder should be added regularly, and the acid pickling solution and pre plating activation solution should be replaced regularly. In addition, the risk of copper impurities should be strictly prevented.

New plating solutions often experience such malfunctions if the purity of the raw materials used is not high. Sodium hydroxide used for electroplating is a solid alkali packaged in iron drums and of qualified quality. However, when using liquid alkali to prepare the tank, the presence of a large number of impurities in the liquid alkali can improve the plating solution.

Distilled water or deionized water is used for the operation of tank preparation. If underground water is operated, the high hardness of the water quality and the high content of Ca2+and Mg2+can easily lead to a decrease in the quality of the coating, resulting in a nearly dense black gray coating. Sometimes, this may cause spots or pinholes in the coating.

Fault phenomenon 2

In some cases, it is not necessary to assume that the phenomenon of blistering on the plating layer occurred during the electroplating process, and the surrounding scenes of electroplating production may also trigger blistering on the plating layer. A certain factory's alkaline zinc salt galvanizing always experiences serious blistering of the galvanized layer from April to May every year, and there is no preliminary notice, so it has to stop production for more than a month every year. Later, after the process inspection, differentiation and creation, when there are some small filaments in the plating solution, the coating blisters seriously. At that time, the season was the flowering period of the wutong trees around the plant area, and their petals were floating in small filaments, more or less falling into the galvanized tank. When the use of weaving rejected the influence of petal like filaments, the problem of blistering in the galvanized layer was eliminated.

The oil stains on the differentiated parts in the notice are all cleaned by chemical degreasing and electrical elimination. But if the monopoly is not appropriate or the oil composition is imbalanced, there may be a small amount of oil droplets remaining in the part profile, which may trigger the foaming of the galvanized layer.

In addition, insufficient activation before plating, without activation, forms a thin oxide film on the part profile, which can also lead to poor adhesion of the coating and foaming.

Similarly, the purity of zinc oxide also directly affects the quality of the coating. Due to differences in the source of raw materials, the quality of zinc oxide varies greatly. It is better to use pure zinc in some cases; if the operation accepts raw materials for production, some low melting point metal oxides (lead added) will be mixed in to improve the plating solution. Therefore, the pre-treatment of alkaline zinc salt galvanizing should be strictly controlled. If the pickling and rust removal time of the parts is too long, it may also stimulate the foaming of the coating due to excessive erosion.