Blackening of the plated layer in the barrel tin plating process is a complex problem that involves a number of factors, including the composition of the plating solution, the process parameters and the post-treatment process. This phenomenon is usually attributed to the following 2 aspects:
Hard chrome additive application process, due to the hexavalent chromium layer is easy to passivate (trivalent chromium chromium plating layer in trivalent chromium chromium plating solution passivation is poor; metal chromium passivation coefficient as high as 0.74, second only to aluminum and titanium), therefore, plating is not allowed to be a very short time in the middle of the power outage (the requirements of the workpiece and the hanging device should be elastic contact, the hanging device and the cathode copper rod to ensure that the conductive is good).
What is chemical degreasing? What kind of steel chemical degreasing powder do you choose to remove oil quickly? Let's take a look at it in this issue's article.
Electroplating plant in the production process using alkaline zinc brightener, if the tank solution is contaminated by iron, copper, lead and other impurities, electrolytic decontamination is required, but the loss of the main salt is large, what is the reason for this?
In the production process using alkaline galvanizing brightener, if the plating solution is contaminated with heterogeneous metal impurities and electrolytic decontamination is required, why is it accompanied by agitation?
When using hard chrome additives, how should the concentration of chromic anhydride and trivalent chromium be controlled to ensure good production benefits?
