Common faults and treatment of chrome plating, black chrome plating process and troubleshooting

1.The workpiece cannot be chrome-plated due to hydrogen penetration.

When an electroplating plant plating a batch of chrome plated parts made of hot-rolled steel plates, due to serious rust on the working surface, the oxide scale is difficult to remove during pickling, and has to extend the time.

The most effective way to solve this problem is to reprocess the surface of the rust and the surface of the shearing process, and the factory has agreed with the cooperating unit to plate the chromium layer after the workpiece is processed to meet the quality requirements.

If this kind of workpiece is ground off the rust first during machining, not only will this failure not occur, but also the surface quality of the workpiece can be improved.

2.Pre-treatment requirements for stainless steel chrome plating.

If you want to obtain a firm chromium layer quality on the surface of stainless steel, you must first completely remove the oxide film on the surface, which is difficult to remove from the solid and dense oxide film.

The workpiece that has been removed from the oil stain is hung on the cathode of the chrome plating tank, and the current density of 5 6 is activated, at this time the surface of the stainless steel will not be deposited on the chromium, only hydrogen is precipitated, these hydrogen atoms interact with the oxide film on the surface of the stainless steel, so that the surface is fully activated, the activation time depends on the film on the surface of the stainless steel, generally in 5min, the film is too thick and needs 8 10 minutes, and then the normal current chrome plating is applied, do not reverse plating, otherwise it is not conducive to the bonding strength.

3.Protection method of chrome plated anode.

The newly cast lead-antimony alloy anode, after being brushed clean (or the old lead-antimony anode after brushing), if it is directly hung into the chrome plating tank, it will quickly generate a layer of yellow lead chromate with poor conductivity, this lead chromate will affect normal use, but if it enters the aqueduct in the case of live electricity, and is treated by the current anode of 5 10A dm2 for 30 40min, the surface of the anode will generate brown lead peroxide, with this layer of lead peroxide, it is difficult to generate lead chromate again, but the anode should still be taken out of the tank after the shutdownand store after washing.

4.How to remove lead chromate from anode.

Removal can be performed by anodic electrolysis in the following solutions.

naoh 70~100g/l v 6~8v

NACO3 70 100G L t Depends on rejection.

If the treatment is not thorough after using this method, it is finally necessary to brush with steel wire, and do not wash with hydrochloric acid, hydrochloric pickling will produce lead chloride, which is not only not suitable to be removed, but also chloride ions are easy to cause pollution when brought into the bath.

5.The hard chrome layer is rusty.

Although the potential of chromium is very negative, it has a strong passivation ability, it itself is very stable in the atmosphere, but there are large voids and cracks in the chromium layer, if a single layer of chrome plating, it is very likely to cause corrosion, for this reason, it is necessary to coat copper or nickel before chrome plating to prevent the base metal from leaking out.

Generally after chrome plating.

Prevention of common failures of chrome plating: and solutions.

Due to the above reasons caused by many product defects and quality hazards in the chrome plating process, how to prevent and deal with the factors that affect the quality of chrome plating, the prevention and solution of common faults, combined with the actual production situation, list the following one - some main methods: 1Poor brightness:

Increase the temperature of the plating solution and adjust the content of chromium valence;

2.Edge burning: reduce the current density, increase the temperature of the bath, and remove excess sulfuric acid with barium carbonate;

3.Poor coverage ability: precipitate too high sulfuric acid with barium carbonate, electrify the cathode with small anode, and reduce the temperature of the plating solution

4.There are brown spots on the surface: sulfuric acid, small anode, cathode electrolysis; 5.

Cracks in the plating: reduce the thickness of the plating layer and increase the temperature of the plating solution;

6.The coating is blooming or dark gray: strengthen the pre-plating treatment, increase the temperature of the plating solution, and use barium carbonate to remove the precipitation; 7.

Poor adhesion force: remove with a wire brush or electrolytic removal with lye cathode, correctly calculate the conductive cross-sectional area; 8.Large area of the center of the part without plating:

Increase the impulse current, step power transmission, and treat the bath liquid with barium carbonate; 9.The surface of the coating is rough and the deposition speed is slow: improve the surface finish of the part and reduce the cathode current density;

10.The coating is dark and dull, so that the surface has pitting: large anode and small cathode treatment bath liquid, analysis of sulfuric acid, precipitation of heavy metals.

Hello dear<>

I'm glad to answer for you, the reasons for chrome plating are as follows: 1. The brightness of the plating is insufficient and the temperature is too low; Excessive current density; The sulfuric acid content in the plating solution is low; High content of trivalent chromium in the plating solution; There are iron impurities and are treated with ion exchange resin. 2. Poor deep plating ability The surface of the anode forms lead chromate with poor conductivity, and the anode is cleaned with a wire brush; High temperature of electroplating solution; Low cathode current density; sulfuric acid content is too high or too low; The chromic acid content is too low; Too much trivalent chromium; There are many iron and chlorine impurities, which are treated with ion exchange resin and electrolyzed respectively 3. Poor pre-treatment of coating peeling; The internal stress of the nickel plating layer is too large, and the nickel plating solution is treated with activated carbon; Poor performance of the intermediate coating 4. There are black flowers on the surface of the copper-tin alloy after chromium, and the temperature of the chrome plating solution is low; Poor activation treatment before chrome plating; powering up too quickly or too slowly; High tin content in copper-tin alloy 5, partial chrome plating, improper installation or poor conductivity; The shape of the part is complex, and an auxiliary anode can be used; The hanger is not well insulated, and can be coated with insulating coatings; Poor pre-plating, with oil or oxide; The current density is too low; The plating parts shield each other 6. The scorching temperature of the plating layer is too low; Excessive current density; The sulfate content is insufficient 7, the concave surface of the coating is colored yellow, and the sulfuric acid is insufficient; The current density is small or there is no current 8. The coating is foggy and the bottom nickel is foggy, and the nickel layer should be checked; 9. The coating is rainbow-colored, and the temperature and current density are not properly matched; The temperature is too high; 10. There are obvious cracks in the plating layer and the temperature of the plating solution is too low; The sulfuric acid content is too high; The current density is too high; Hello to the pre-treatment of bad pro!

That's my <> on this issue

Summary. Okay, don't worry, what kind of fault is this?

Okay, don't worry, what kind of fault is this?

What to do about this phenomenon?

Wait a minute, I'll help you check the situation first.

You have black streaks that are unevenly colored, right?

There are two possibilities for this to happen:1The concentration of the stabilizer is not enough. 2.When the cylinder is opened, the concentration of the coordination agent is too high.

Don't worry, you can rule out the cause of the dosage of the black agent, because the black is uneven.

At the same time, when you are operating, you must pay attention to your own safety while standardizing the operation.

Haven't solved the problem yet?

It's black chrome off!

Okay, big wait a minute, the small ones will help you tidy up right away.

Take a big look at whether the surface treatment at the beginning is not done well, and the rolling plating parts can be cleaned with propanol at the beginning, and then treated with activating liquid, such as chrome plating, it is best to remove the carbon wheel first.

Is there no problem with chrome plating? That's it after the black chrome plating.

I activated it with hydrochloric acid before plating the black chrome.

Well, this is indeed a bit troublesome, don't worry, kiss, I'm working hard here. I want to confirm with Da Da, the dosage of additives should be fine, right?

Let's exclude them one by one.

1.Will the electrolytic acidity be too large? Or is the temperature too low?

Solution: Neutralize the electrolyte with alkali and heat it.

2.Is the current too strong?

I don't think the kiss should notice this, just make it smaller.

3.Is there anything that needs to be adjusted when preparing the product?

This will definitely be solved.

4.Impurities in the electrolyte can also cause the situation in your diagram.

That's when we need to get rid of the impurities.

Generally speaking, these are the cases, if it can't be solved, then we can only find the manufacturer and see what other ways they have.

Coating peeling: Improper current density of the chrome plating anode of the mold affects the adhesion of the plating. The current density is too large, resulting in the hard chrome plating layer is easy to fall off, so attention must be paid to controlling the cathode current density within the specified range of the process.

SIF6 in the plating solution; If the content is too high, it will also make the black chrome plating easy to fall off.

Poor wear resistance of hard chrome plating: The comparison of production practices shows that the improper content of the main components has an impact on the wear resistance of the black chrome plating. If the content of CRO3 in the plating solution is less than 250g L, the wear resistance of the plating layer is poor, and H3BO3.

When the content is less than 20g L, the coating is coarse in crystallization, and the hardness and wear resistance will be reduced. In the electroplating process, the cathode and anode area ratio is not properly controlled, and the proportion is out of balance, which will also reduce the wear resistance of the plating, usually the cathode and anode area ratio is 1:5 to 1:

The range of 1o is more favorable.

The thickness of the hard chrome plating layer is not enough; Manufacturers cut corners and the processing time is not enough.

Some common problems of hard chrome plating, their causes and solutions???

Hello Wang Naihe, dear, I am happy to answer for you:1The local surface is not trapped and plated with chromium layer 2

The plating peels off 3The plating is coarse and grainy. The metal is hard and brittle.

The Mohs hardness is 9. Usually electrochrome plating is the final treatment of metal components, which will be plated with a thin layer, which is used to resist minor scratches and aesthetics. Its effect is stronger than that of silver paint.

The grinding machine of the material should be completed before the electroplating. If you use it as a physical punch, it will naturally collapse. I hope mine can help you.

Summary. Some common problems of hard chrome plating, their causes and solutions??? Hello dear, the design of the hanger is unreasonable.

If the design of the hanger is not reasonable, an air pocket is formed on the surface of the workpiece, and due to the accumulation of gas, the liquid is discharged, and there is no plating solution in this part, and it is difficult for chromium ions to be discharged, and a plating layer is formed. Solution: Design a reasonable hanger to avoid the formation of air pockets on the surface of the workpiece.

The local oxides of the matrix are not removed. Treatment method: Strengthen the pre-plating treatment to ensure that the substrate reaches the "pure electroplating" surface.

I hope my answer is helpful to you, and finally I wish you good health and a happy mood again!

Some common problems of hard chrome plating, their causes and solutions???

Some common problems of hard chrome plating, their causes and solutions??? Hello dear, the design of the hanger is unreasonable. If the design of the hanger is not reasonable, an air pocket is formed on the surface of the workpiece, and the liquid is discharged due to the accumulation of gas imitation cultivation, and there is no plating solution in this part, and the chromium ions are difficult to discharge, and the plating layer is formed.

Handling method: design a reasonable hanger to avoid the formation of air pockets on the surface of the workpiece. The local oxides of the matrix are not removed.

Treatment method: Strengthen the pre-treatment of plating to ensure that the substrate reaches the "pure electroplating" surface. I hope my answer is helpful to you, and finally I wish you good health and a happy mood again!

The hard inscription comes out and is placed in ** easy to be tempted.

Hello dear, chrome furniture should not be placed in a damp place, Xuancheng hard chrome plating, otherwise it is easy to rust, and even cause the plating to fall off. If the chrome plating film is washed away, if there is a yellow-brown 1 mesh spot, it should be wiped frequently with neutral engine oil to prevent it from spreading and expanding.