Views: 317 Author: Site Editor Publish Time: 2022-08-04 Origin: Site
Do you know what salt spray test is? In fact, it is a common test which is mainly used to check the corrosion resistance of some items and their surface coatings. It is simple and fast comparing with other test methods, so it is widely used for the products coated with corrosion protection layer such as coated metal zipper, metal zipper head and plated zipper pullers etc. We know that metal zipper products including metal zipper teeth and zipper pull pieces need to be plated a protective layer in order to prevent metal parts from corrosion when contacting water or moisture.
The purpose and scope of application of the salt spray test
The GB10587-89 salt spray test chamber technical conditions clearly stipulate the structure and appearance requirements of the salt spray test machine, and the temperature test method and the test method of the salt spray sedimentation rate. The salt spray test is mainly used in the following aspects:
1. Assess the salt spray corrosion resistance of the test material and its protective layer.
2. Evaluate the difference in the ability to resist salt spray corrosion of the same product with different manufacturing methods.
3. According to different protective coating processes, the level of its salt spray corrosion resistance.
4. Assess and compare the salt spray corrosion resistance of similar products produced by different manufacturers.
5. Study the possibility of electrochemical corrosion increased due to the combination of metals.
At present, the domestic salt spray test is based on three standards:
1. GBT 2423.17-81 copper accelerated salt spray test (CASS).
2. GBT 10125-2012 artificial atmosphere corrosion test, salt spray test.
3. Determination of GBT 1771-2007 paint and varnish resistance to neutral salt spray.
For metal zipper factories and zipper slider factories, the common standards used for Salt Spray Test are ASTM B117, ASTM D2059, ISO9227 and SBS (QS-QA-054).
When providing a plated metal zipper to Salt Spray Test, the necessary steps that should be considered as below:
1. First of all, prepare two similar samples, one is for test, and another one will be used for comparison that won't be exposed to the test.
2. When testing, the zipper should open 1/2 of its length, and hung it on the rod in the chamber of machine vertically.
3. The temperature within the chamber should be kept for 24 hours between 33oC-36oC.
4. The metal zipper sample can be taken out after 24 hours, and then rinse it under the tap water at room temperature. At the same time, excess water on sample must be blown off through stream of air.
5. After that, the sample can be put on a horizontal surface to dry at room temperature.
6. It is necessary to observe the degree of corrosion of the sample used for test through visual observation comparing with another zipper sample for control. And the zipper must be pulled open and close for around 10 times.
7. After finishing all the primary corrosion tests, the durability and strength of zipper must be measured, since it is an indicator of the corrosion effect on the sample.