What is ASTM B117 salt spray test?
ASTM B117 is a salt spray test used to produce relative corrosion resistance information for specimens of metals and coated metals exposed in a standardized corrosive environment. Micom offers ASTM B117 accelerated corrosion testing as part of its surface finish and accelerated aging testing services.
How long is a salt spray test?
The tests typically last from 8 to 3,000 hours and employ a 5% sodium chloride solution with a pH between 6.5 and 7.2. There are a variety of other corrosion tests, but the salt spray test is very standard, even though there is some disagreement about how closely it recreates real life conditions.
What are salt spray hours equivalent to in years?
I don’t want to bore you with more test methods, but as you can see there are reasons for tests other than salt spray. My references indicate that approximately 100 hours salt spray is similar to one year outdoors based on OEM testing in the US.
How do you perform a salt spray test?
Salt spray tests are conducted in a closed testing chamber. A salt water solution is applied to a sample via a spray nozzle. This dense salt water fog is used to imitate a corrosive experiment. After a period of time, which is dependent on the corrosion resistance of a product, the appearance of oxides is evaluated.
How long is corrosion testing?
Test duration ranges from 24 hours to 1000 hours or more. There are some obvious reasons why the salt spray test does not correlate with real-world exposure conditions, in particular: The surface of the test coupons is constantly wet, with no cyclic drying, which does not happen in reality.
How does the salt spray test hours correlate with real world duration?
It should be noted that contrary to what many people think or expect, the Salt Spray Test, just like other corrosion tests does not correlate anything. The test for X hours is not an indicator of any number of years that coating will resist corrosion. This is because, in real life situations, rust takes years to occur.
Which coating is tested by salt spray test?
This test can be used to test the relative resistance to corrosion of paints on steel when exposed to a changing climate of dilute salt spray at ambient temperature, followed by air drying at elevated temperature. It is a popular test in the surface coatings industry, where it is also referred to as the PROHESION test.
What happens to stainless steel in saltwater?
This is why some grades of stainless steel are better at resisting corrosion from saltwater than others. However, this passive layer does not make stainless steel immune to corrosion. Stainless steel can, in fact, rust and corrode if continuously exposed to saltwater or other corrosive conditions over time.
How do you protect stainless steel from salt and air?
- Sand away any rust present on the stainless steel with a block of very fine-grit sandpaper.
- Wipe the stainless steel’s entire surface clean with a soft cloth moistened with denatured alcohol.
- Apply a corrosion-resistant coating to the stainless steel to protect it from salt air.
Is code for salt spray test?
Micom Laboratories now offers ISO 9227, an international standard for salt spray tests.
How long does it take to test stainless steel with salt spray?
Comparison of 316, 304 and 430 type stainless steel in salt spray testing Results from one testing laboratory, based on tests done to the ASTM B117 method suggest a 316 type part could be expected to pass a 96 hour test using a 3% salt spray. Indications are that longer test times would not be expected to give satisfactory results.
Can a 304 steel part be tested in 3% salt spray?
In contrast, 304 type parts would not be expected to give satisfactory results in a 3% salt spray, but if the salt solution concentration is reduced to 0.3 %, then it is possible that a 304 type parts may be satisfactory for test times up to 120 hours. This could also apply to 430type ferriticor 431 type martensiticstainless steel parts.
How long does a salt spray test take?
BS7479:1991 – Method for Salt Spray CorrosionTests in Artificial Atmospheres. This supercedes BS5466:1977 and is equivalent to ISO 9227. The test duration’s range from 2 to 96 hours. The pass / fail criteria is that thers should not be any ‘visible’ staining on parts tested.
Is the salt spray test a universal test?
The salt spray test is the oldest “corrosion test” and the most widely used by users of highly corrosion- resistant material. It has become a “universal” test. The reason is that the salt spray test offers numerous advantages. One of the most interesting is that the test is multi-material.