Technical data

We would like to introduce the details of various corrosion resistance tests (neutral salt spray test, acetate spray test, cas test, ferroxyl test).

Corrosion resistance test

Evaluation and criteria for corrosion resistance of decorative plating

According to the JIS standard, "nickel and nickel-chrome plating (JIS H 8617)" and "decorative electroplating on plastic (JIS H 8630)" are associated with the specifications of decorative plating, corrosion resistance test conditions, and operating environment conditions. Corrosion resistance is specified in. On the other hand, for decorative gold plating (JIS H 8622) and decorative silver plating (JIS H 8623), the standard of corrosion resistance is based on the regulations between the parties to the delivery.

The regulations for nickel-chrome plating and decorative plating on plastics stipulate corrosion resistance as follows.

(1) Define several stages of product usage environment.

(2) Specify specifications such as the plating configuration and minimum thickness used in the environment.

③ Specify the corrosion resistance test that the plated product used in the environment should be satisfied with.

[Grade, composition and minimum thickness of decorative plating on plastic]

[Grade, composition and minimum thickness of decorative plating on plastic]

[Corrosion resistance test time for decorative plating on plastic]

This standard requires a rating number of 8 or higher after performing a corrosion resistance test for a specified time or cycle.

Grades 1 to 5 correspond to the environment in which plated products of that specification can be used.

For example, the grade of the product with gold plating or silver plating on the top layer is 1st grade or 2nd grade, so it can be used only in the indoor environment of the usage environment number 1 or 2.

When the tin alloy plating is the top layer, the grade differs depending on the type of nickel plating and the minimum film thickness, and it can be used for the usage environment numbers 1 to 3.

The top layer must be chrome-plated for use in usage environments 4-5.

Use environment number 3 that may get wet with rain or dew, or use that can be used outdoors has two or three layers of nickel plating, the film thickness must be 20 μm or more, and the top layer is tin-cobalt alloy plating or It will be plated with cobalt-nickel alloy.

On top of that, the Cass test must be performed for 16 hours or the neutral salt spray test for 8 hours per cycle for 2 cycles, and the rating number must be 8 or higher.

Neutral salt spray test

This is a test method to check the corrosion resistance of plating by repeatedly spraying a neutral sodium chloride solution, drying, and exposing it to a moist atmosphere using a salt water spray cycle tester.

* Corrosion resistance test such as galvanization and chromate treatment

[Test conditions for neutral salt spray cycle test method]




Other corrosion resistance tests

[Acetic acid spray test]

This is a test to check the corrosion resistance by spraying acetic acid-acidic salt water.

Perform a salt spray test at pH 3.1-3.3. (Same as the neutral salt spray test except for pH)

[Cass test]

This is a test to examine the corrosion resistance by spraying acetic acid-acidic salt water whose corrosive action is promoted by adding copper salt. (PH 3.0-3.2 50 ± 5 ℃)

* The final application is for chrome-plated products.

[Feroxyl test (perforation test, blue spots)]

This is a corrosion resistance test for copper-nickel, nickel-chromium, and copper-nickel-chromium on iron ground.

The judgment method is represented by a rating number.

(Represented by 1 to 10 depending on the corrosion area. 10 has good corrosion resistance)

[Main test conditions for neutral salt spray test and Cass test (JIS H 8502)]


Connection Co., Ltd.

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