The use of high sulfur nickel additives can obtain nickel plating with sulfur content of 0.12%~0.25%, which is mainly used for the protection of steel, zinc alloy substrate and the intermediate layer of decorative plating, and can effectively improve the corrosion resistance of the plating. So how should we maintain the plating solution when using high sulfur nickel additives?
Bigely Technology has analyzed according to the field experience and the characteristics of the product, mainly for the following five reasons:
1. Control of plating solution temperature. As the temperature rises, the cathode current density will increase and the plated layer will have a better appearance. However, if the temperature is too high, the plating layer will be rough, and the sulfur content of the plating layer will decrease with the increase of plating solution temperature. So the temperature of plating solution should be controlled at 40-45℃.
2、Control of plating solution pH value. The pH value of plating solution is controlled at 3.8~4.2, the high pH value of plating solution can easily produce Ni(OH)2 and affect the bonding force between plating layers. pH value is too high, dilute sulfuric acid can be used to adjust. Note: Only when the chloride content in the plating solution is too low can dilute hydrochloric acid be used to adjust the pH value.
3. Addition of high sulfur nickel additive. General high sulfur nickel additive Ni-320 consumption of 500-600ml/KAH, saccharin consumption of 20-30g / L, in order to maintain the consistency of the sulfur content in the flash plating layer, Ni-320 should be added in small quantities, add too much plating is easy to peel. In the production process, the additive replenishment interval should not exceed 4 hours.
4, stopping time. Workpiece plating after high sulfur nickel stopping time should not be too long, long time plating layer is easy to passivate, so that the high sulfur nickel layer and bright nickel layer of the combination is not good.
5. Control of potential difference. In production, should often measure the workpiece nickel layer potential difference, if the potential difference exceeds -120 ~ -150mv, can use activated carbon and sulfuric acid joint treatment. As the adsorption capacity of activated carbon can not reach 100%, it can only adsorb 50% of the additives, so the additives should be supplemented in accordance with the general amount of supplementation.
In the process of using high sulfur nickel additives, follow the maintenance methods provided by Bigely, which can reduce malfunctions and also keep the plating quality good. If you are interested in high sulfur nickel additives, please contact Bigely customer service for free samples and detailed technical information!
