There are three distinct test method in ISO the neutral salt spray (NSS), the acetic acid salt spray (AASS), and copper-accelerated acetic. ISO NSS. adv. auto technology banner. A discussion started in but continuing through Q. We have a customer, that we supply some zinc. The salt spray (or salt fog) test is a standardized and popular corrosion test method, used to Other important relevant standards are ISO, JIS Z and ASTM G The most common test for steel based materials is the Neutral Salt Spray test (often abbreviated to NSS) which reflects the fact that this type of test.
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Although there may be a weak correlation between the duration in salt spray test and the expected life of a coating in certain coatings such as hot dip galvanized steelthis test has gained worldwide popularity due to low cost and quick results.
In either case, the exposure to salt spray may be salt water spray or synthetic sea water prepared in accordance with the requirements of the test standard.
Requirements are agreed between customer and manufacturer.
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March 16, A. What is major difference between ISO [link by ed. This is followed by 2. So this information should not be used as a substitute for referring to a complete test standard, at an appropriate revision level.
For this reason the salt spray test is most often deployed in a quality audit role, where, for example, it can be used to check the effectiveness of a production process, such as the surface coating of a metallic part. Salt spray testing is popular because it is relatively inexpensive, quick, well standardized, and reasonably repeatable. Is there any equivalence between this two standards?
Is it possible to reduce test duration by some accelerated Testing? Toby Padfield – Troy, Michigan. Such tests are commonly referred to as modified salt spray tests.
This is followed by 0. I’ll really appreciate your help A requirement that a component ‘pass’ an accelerated corrosion test isn’t often meaningful until the finishing spec tells you what that means: It does not specify the dimensions or types of test specimens, the exposure period to be used for a particular product, or the interpretation of results.
There is a general historical consensus that larger chambers can provide a more homogeneous testing environment. Painted surfaces with an underlying hot-dip galvanized coating can be tested according to this method.
Options include the following:.
Although the majority of salt spray tests are continuous, i. Testing periods range from a few hours e. ASTM B was the first internationally recognized salt spray standard, originally published in This test is also referred to as an ASS test. Both are excellent browsers.
ISO – Corrosion tests in artificial atmospheres — Salt spray tests
George Gorecki – Naperville, Illinois A. You isi then need to talk to your customer about the possibility of using one specification in lieu of the other. Salt spray testing is an accelerated corrosion test that produces a corrosive attack to coated samples in order to evaluate mostly comparatively the suitability of the coating for use as a protective finish.
Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises the following 2 part repeating cycle. Brian Terry has directly answered your question, but please post your situation rather than an abstract question so that readers can best help you. Though believed to be accurate at the time of writing, this may change ns time. But benchmarking performance is something altogether different.
Equivalence between ASTM B-117 vs. ISO 9227 NSS
This 922 arises through the use of chemically altered salt spray solutions, often combined with other test climates and in most cases, the relatively rapid cycling of these test climates over time. For 9272, a typical electroplated zinc and yellow passivated steel part lasts 96 hours in salt spray test without white rust.
Retrieved from ” https: The second climate cycle comprises 0. This is followed by 1. The salt spray test is one of the most widespread and long established corrosion tests. The number of cycle repeats and therefore the test duration is variable.
Life cycle A standard is reviewed every 5 years 00 Preliminary. Results are represented generally as testing hours in NSS without appearance of corrosion products e. I suggest that you send some parts out for testing according to the ISO standard to see if they meet the spec.
This climate is maintained under constant steady state conditions. Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, prepared in accordance nsw the requirements of the test standard and acidified to pH 3.
ASTM G85 is an example of a test standard which contains several modified salt spray tests which are variations to the basic salt spray test.