Plating decorative chromium common faults and corrective methods

Insufficient brightness

a) low temperature or high current density

b) low sulfate content

c) trivalent chromium high

d) high iron impurity content

a) Temperature rise , check if the current is in the process range

b) Analysis supplement

c) large anode , small cathode electrolysis

d) Electrolysis with ion exchange or membrane

Poor coverage

a) high temperature and low current density

b) high sulfuric acid content ,

c) insufficient trivalent chromium

d) More impurities such as zinc, copper and iron

a) lower , check if the current is in the process range

b) after the analysis, use BaCO3 to remove part of the sulfate;

c) large cathode , small anode electrolysis

d) ion exchange or diaphragm electrolysis

Partial chrome free layer

a) The hole is not blocked

b) improperly mounted, resulting in airbags or poor electrical conductivity

c) The shape of the part is complicated, no auxiliary anode is used

d) Part mutual aid shielding

e) oil stain on the surface of the plated parts

f) the hanger is not insulated

a) blocked with plastic tube

b) use the hanger

c) Select the appropriate auxiliary anode

d) less hanging parts

e) Reprocessing the plated parts

f) Improve the insulation of the hanger

The chrome layer is peeled together with the nickel plating

a) Incomplete treatment before plating

b) The internal stress of the nickel plating layer is large

a) Strengthen plating treatment

b) Adjust the nickel plating solution

Black flowers appear on chrome plating on copper-tin alloy plating

a) low solution temperature

b) Incomplete treatment before chrome plating

c) Power is too fast or too slow

e) The tin content in copper-tin alloy is too high

a) elevated temperature

b) Strengthen chrome pretreatment

c) improved operation

e) Adjusting copper-tin alloy

Hard chrome plating

Plating

a) Poor treatment before plating

b) Power off during chrome plating

c) The parts are warmed up in the tank.

d) The solution temperature or cathode current density changes too much

e) too high sulfuric acid content

a) Strengthen plating treatment

b) When re-chrome plating, anodizing or cathodic small current activation treatment

c) lengthen warm-up time

d) Strict control of solution temperature and cathode current density

e) treatment with strontium carbonate

The cast iron parts are not plated with chrome.

Hydrogen evolution only

a) excessive etching before plating

b) causing graphite exposure when performing anodizing

c) cathode current density is too low

a) Re-plating after full processing

b) Re-plating after full processing

c) increase the cathode current density

Rough coating with chrome

a) The cathode current density is too large

b) the distance between the anode and the anode is too close

c) The shape of the part is convex, no protective cathode is used

d) too high sulfate

a) reduce cathode current density

b) Relax the distance between the anode and the anode

c) use a suitable protective cathode

d) treatment with strontium carbonate

Significant cracks on the coating or underlying metal

Steel has stress during quenching

Tempering parts to eliminate stress before plating