Third Party Inspection of Zn Plated Products
Third-Party Inspection of Zn Plated Products
Third-Party
Inspection of Zn Plated product – In this Technical information – we have explained
the following related to Zn Plating / Zn Plated Products
-
About
Zn Plating
-
Zn
Plating Process
-
Application
of Zn Plated products and its Benefits
-
Inspection
/ CheckPoints
-
Reference
IS Standards for Zn Plating
-
Defects
of Zn Plating
-
Inspection
and Testing procedures for Zn Plating products/Processes
-
Instruments
used for Inspection and Testing
The
purpose of providing this information is to develop a sound understanding and knowledge
of Third Party Inspection of Zn Plated products / Zn Plating process. So that inspectors
performing Third
Party Inspection services can apply knowledge to perform the Third-Party
Inspection of Zn Plated products / Zn Plating process and provide the optimum output of Inspection of Zn Plating process/ Zn Plated Products.
Zinc
Plating
Zinc plating, a process also known as galvanization, is the deposition of a thin layer of Anti Corrosion on the metal component to provide a protective
layer. The outer surface of the zinc coating
oxidizes to form zinc oxide,
which results in a matte silver-color finish.
Zinc Plating is
primarily used to protect metals from corrosion effects. Zinc coating prevents the corrosion of protected metal by forming a physical barrier. Zinc and iron/ steel
are joined and placed in an electrolyte a cell is formed in which the zinc
becomes the anode and the steel the cathode. Then, the zinc is sacrificed, and
the steel does not rust.
Process of Zinc
Plating
1.
Cleaning of Surface: -This is done to eliminate any rust, oil,
and dirt from the components. It’s best to use an alkaline detergent to ensure
the zinc plating remains intact for a good period of time. The cleaning process
involved putting the metal in a bath for 5-10 min at 150 to 200◦ F to take out
the dirt. This is followed by an acid treatment that helps eliminate surface
rust.
2.
Preparation Of Plating Solution: - zinc plating
requires immersion of the component into a unique electrolyte solution(Acid
zinc, Alkaline zinc, etc), which is also known as a plating bath. The bath
consists of the zinc metal ionic solution and various chemicals that facilitate the plating process. They also help produce the desired chemical and physical
properties of the finished product.
3.
Choosing Zinc Plating process:
-After
Solution preparation, the parts are ready for plating The chosen method could
involve rack plating where larger parts are fixed to the metal rack which is
placed inside the tank. Barrel plating is normally used for smaller parts; the
parts are placed inside a barrel and rotated.
4.
Introducing the
electrical Current: -
Electroplating is also known as electrodeposition because an electrical current
is used to deposit metal ions onto the surface of the components.
5.
Post- Treatment Procedure:
-Completion
of electrodeposition, the parts ready for post-treatment. This involves rising
the parts in water to remove any contaminants and plating bath remnants. The
final step is to dry the zinc-plated parts
Factors Impacting
Zinc Plating Results
1.
Current Density: -The current density
significant impact on the thickness of the zinc coating. If the higher the current
density, the greater the thickness coating.
2.
Temperature: - The temperature of
the plating bath will also have a direct impact on the zinc plating coating. Higher
bath temperature increases the consumption of brighteners and other additives.
3. The concentration of Zinc Deposit: The level of zinc
concentration in the plating solution will affect the brightness and texture of
the plated product. A higher concentration will produce a rougher surface, while
lower concentration results in a brighter finish.
4.
Other controllable
factors that affect the result:-
5.
Components
Surface Condition
6.
Duration
of actual plating time
7.
Efficiency
of the rinsing operation
8.
Position
of anode and cathode
Zinc Plating
Applications & Benefits
1.
Zinc The coating can provide a corrosion-resistant coating on smaller and larger parts.
2.
Zinc
coating increases the strength of the components
3.
Zinc
is capable of tolerating temperatures of up to 120◦ F which can help lower
cooling cost.
4.
Zinc
is an extremely ductile metal
5.
Friendly
to the environment
6.
Flexibility
7.
Low
Cost
IS Standards for
Zinc Plating
1.
IS:
1572-1986-Specification for electroplated coatings of cadmium on iron and Steel.
2.
ASTM
B633-19-Standard for electrodeposited coating of zinc on iron and steel
3.
IS
10173:1982-Zinc alloy die casting for electroplating
4.
IS
10209:1982-Specification for electroplated coatings of alloy tin-lead
5.
IS
2633 (1986 )-Method of testing uniformity of coating of zinc
Defects in Zinc
Plating/ Zn Plated Products
1.
Cold
Shut
2.
Pitting
3.
Sharp
Edge
4.
Cleavage
Points
5.
Unclean
Manufacturing
6.
Loss
Of Adhesion
7.
Cracking
After Plating
8.
Dull
and hazy Deposits In Plating
9.
Blistering
in plating
10. Oxidation in plating
Inspection and
Testing Procedure& types of Zinc Plating
1.
Sampling- The number of samples
to be tested shall be as specified in the material specification.
2.
Preparation of Test
Piece-A the test piece shall be cut off from a sheet selected as per material
specification.
3.
Cleaning of sample-The test piece shall
be cleaned with a volatile organic solvent
4.
Copper sulphate
solution preparation-The the specific gravity of the test solution during the test shall be 1.186 at 18 ± 2◦
C. Adjustment may be made by adding distilled water.
5.
Interpretation OF Test-Specified the number
of dips, when the test piece is finally rinsed and wiped dry, it does not show
any adherent red deposited of copper upon the base metal.
6.
Number of Dips-The sample shall be
subjected to four successive dips in the solution, each lasting one minute.
7.
Supplementary Test (Microscopic
Test)-The
test piece through the copper deposit mounts and polishes it
metallographically.
8.
Qualitative Test for
Zinc-Apply
a drop of dilute hydrochloric acid to the area in question (depending on its
size).
9.
Water Immersion Test-Partially immerses
the test piece in distilled water at room temperature.
Instruments Used for
Zinc plating Inspection
1.
Universal
tensile testing machine
2.
Salt
Spray chamber
3.
Adhesion
test chamber
4.
Elco
meter
5.
Knife
for knife test
Most Common Intended use of Zn plating products
1.
Automobile
Parts
2.
Machine
Parts
3.
Industrial
Use
4.
Home
Appliances
Third-Party
Inspection Agency in India
We
are a leading Third-Party
Inspection Agency in India providing Third Party Inspection services in many
industrial sectors including Zn Plating process / Zn Plated products.
We
have a sufficient number of professional engineers with vast industrial experience
in many industrial sectors. Any organization looking for Third Party Inspection
services may contact us.
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