A JIS Mark of electro galvanized plating
A JIS Mark of electro galvanized plating
1．Type and Grade
Remarks 1，Type 1 A is plating only or dipped in Nitric acid.
2，Type 1 B is Bright chromate treated
3，Type 2 is Coloured treated
4，The minimum thickness of plating does not include the film of chromate
2．Meaning of terms
Chromate treatment indicated creating the corrosion-proof film against zinc and chemical polishing action.
Sheen chromate means giving sheen to the plating by chromate treatment.
The film of chromate for corrosion-proof is thick and coloured. For that reason corrosion-proof chromate film is called coloured chromate. The tone of colour changes.
The external appearance of plating-To test the external appearance of plating we have to examine the degree of sheen, unevenness of sheen, unevenness of clour, dimness, stains, bulges, scratches, pits, exfoliation, cracks, exposure of base metal and defects caused by usage. These defects must be eliminated. When using chromate treatments we don’t recognize unevenness of colour as a defect.
The minimum thickness of plating- The minimum thickness of plating can be checked in the previous list. After various tests the results are printed in the list.
Corrosion resistance of chromate film- When doing tests on the corrosion resistance of chromate film Type 2 Grade 2-6 it is possible to get results within 48 hours. If the chromate starts to turn white it means that corrosion has set in and is quickly identified. However Type 1 A and Type 1 B and Type 2 Grade 1 are not subjected to the tests. (notes) Type 1 B and Type 2 Grade 1 testing times are set according to an agreement with Micro-Ace and the customer
Plating adherence- When doing test on adherence capabilities we are looking for exfoliation and bulges on the surface.
Base metal stress removal- Before plating the base metal is subjected to heat treatment according to an agreement between Micro-Ace and the customer.
Removal of hydrogen embrittlement-When removing hydrogen embrittlement the heat treatment process must take place within 4 hours after plating. The heat treatment must be between 190℃〜230℃. The suitable temperature and the length of time are set according to an agreement with Micro-Ace and the customer.
External appearance test- External appearance test results are on another list so we have omitted it here.
Thickness test- Micro-Ace uses one of the following methods to check the various thickness using sections checked by microscope, magnetism electrolysis, and X-rays. These tests are according to JISH8501 regulations
Chromate film corrosion resistance test- These tests are according to JISH8502 regulations using saltwater spray continuously for 48 hours on the chromate film. The sample used for testing must be left standing for at least 24 hours before the tests commerce
Adherence test- Adherence tests are according to JlSH8504 regulations.
The following are a list of tests.
（1）Plating tests are done according to rigid quality regulations
（2）Tests are done according to JISZ9031 using parts from the same lot or the same category.
Note l．The tested item and the kind of test are set according to an agreement with Micro-Ace and the customer.
2．The amount of tests, the order of tests, the part of the sample to be tested, and what the sample is to be used for are set according to an agreement with Micro-Ace and the customer.
Plating terminology is listed in the following order :
Plating types, base metal, minimum thickness of plating
Example 1．Electro galvanized plating on steel with thickness 20μm
EP-Fe／Zn 20 or EP-Fe／Zn(5)
Example 2．Electro galvanized plating on steel with thickness of 8μm. Sheen chromate is used as an after treatment.
EP-Fe／Zn 8／CM1 or EP-Fe／Zn(3-C1)
Example 3．Electro galvanized plating on steel with thickness of 5μm. Coloured chromate is used as an after treatment.
EP-Fe／Zn 5／CM2 or EP-Fe／Zn(2-C2)
Indication of the following items on the invoice.
（1）Types or levels or symbols of these
（2）Processing date or code of it
（3）Processing company name or code of it