1.Incomplete degreasing of workpieces

2. Oil contamination in plating bath

3. Excessive organic decomposition byproducts

4. Insufficient sodium phenylsulfinate

5. Poor-quality sodium dodecyl sulfate (SDS/SLS)

1.Optimize degreasing solution formula and process parameters

2. Purify the plating bath

3. Activated carbon treatment of bath

4. Supplement 0.1～0.2 g/L sodium phenylsulfinate

5. Purify bath with activated carbon

1.Oil contamination of plating solution

2. Sludge falling from anodes or foreign suspended impurities

3. Insufficient wetting agent

4. Overabundant organic degradation products

5. Excessively high Fe³⁺ concentration

1.Full bath purification

2. Replace anode bags and filter the solution

3. Add appropriate amount of wetting agent

4. Activated carbon purification

5. Adjust pH to 3, perform low-current electrolysis or add 2～4 g/L reduced iron powder

 for reduction

1.Excessively high bath pH

2. Overhigh ferric ion (Fe³⁺) concentration

3. Organic impurities in solution

4. Heavy metal impurity contamination

5. Unbalanced nickel‑iron ion ratio in bath

1.Adjust pH with carbonic acid or hydrochloric acid

2. Set pH=3, electrolytic treatment or reduced iron powder addition

3. Remove organics via activated carbon filtration

4. Low-current dummy electrolysis for metallic impurity removal

5. Readjust Ni/Fe concentration proportion

1.Too low chloride ion concentration

2. Insufficient stabilizer content

1.Adjust chloride content as required

2. Supplement stabilizer appropriately

1.Deficient saccharin dosage

2. Excessive ferric iron (Fe³⁺)

3. Excess organic impurities

1.Top up saccharin properly

2. Adjust pH to 3 followed by electrolysis or reduced iron powder treatment

3. Purify bath with activated carbon

1.Low bath pH

2. Excessively high operating temperature

3. Overhigh Fe³⁺ concentration

4. Shortage of secondary brightener

5. Excessive metallic/organic contaminants

6. Over-concentrated citrate content (sodium citrate)

1.Fine-tune bath pH value

2. Control bath temperature to specified range

3. Adjust pH=3 then electrolysis or iron powder reduction

4. Replenish secondary brightener moderately

5. Conduct conventional impurity removal treatment

6. Dilute plating bath with pure water properly

1.Overhigh ferric ion content

2. Accumulated organic breakdown products

1.Adjust pH=3 + electrolysis or reduced iron powder treatment

2. Activated carbon treatment; combine activated carbon & hydrogen peroxide treatment

 if needed

1.Improper pre-treatment process

2. Insufficient stabilizer

3. Current interruption during plating

1.Revise pre-treatment workflow

2. Analyze bath composition and supplement stabilizer based on test result

3. Inspect all conductive connections and fixtures

1.Insufficient brightener

2. Low plating temperature

3. Undersized operating current density

4. Insufficient total anode area