13 Aug Scope—The SAE J lab test procedure should be used when determining cosmetic corrosion performance for a particular coating system. SAE J Cosmetic Corrosion Lab Test. This test procedure has been field correlated, so it is claimed that the results obtained should correlate well to those . Salt Spray test (ASTM B) with exposures up to hours and the Cyclic Corrosion test (SAE J) with exposures up to and cycles. The latter.
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The number of cycle repeats and therefore the test duration is variable.
They drove the trucks for five years and then measured the corrosion performance of the materials. The industry required a more predictive method of testing which would allow component performance to be addressed before field trials and product releases.
The samples must be subject to an application of salt solution consisting of the following formulas and by use of one of three methods shown as follows; 0.
Canadian on-vehicle tests were conducted at Montreal, Quebec and St.
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The researchers then tested the standard materials with many different test methods, including SAE Jand then statistically analyzed their results to see which test method offered the best correlation to the real-world test results. As shown in the following figure, one test cycle requires 24 hours and has three stages.
Spray Method — periodic or continuous direct impingement spray of the salt solution over the 15 minute interval that ensures that the test specimens are kept wet for the entire 15 minute interval. At least two substrates were chosen because the existence of proven corrosion testing results enabled them to be used to assure the consistency of the test.
When this is the case, you extend the dry stage over the weekend. As a result of early experience, the automotive industry took a lead role in the development of cyclic corrosion tests with the objective of producing results that better correlate with field exposure.
Contact Ascott for Further Information. While the results so far have been very good, the researchers are continuing to refine and improve the test, in an effort to improve both the repeatability and reproducibility of the test. Researchers are also working on improving the method for salt application. These differences can lead to differences in test results. When running the test automatically, you do not need the extended dry stage.
You need to upgrade your browser You are using Internet Explorer 8 This is considered an out of date browser. The result is that salt spray test methods produce different corrosion mechanisms and different corrosion products than the more realistic, but more expensive, outdoor testing. This group strived to develop the knowledge of corrosion mechanisms and their replication in a controlled environment until, nearly 20 years later and after considering over available laboratory, proving ground, and outdoor corrosion tests, the SAE Surface Vehicle Standard, J Cosmetic Corrosion Lab Test, was published in June The SAE J test showed the best correlation.
For one thing, parts tested in a salt-spray cabinet are continuously wet, while those parts on a vehicle experience periods of wetness and dryness.
One of the first steps was to develop a set of standard materials that the researchers could use to compare the laboratory tests to outdoor on-vehicle tests. Immersion Method — test specimens immersed in the salt solution for a 15 minute interval of each test cycle. The development swe SAE J was time consuming, but thorough. In this context they can be considered to be equivalent and interchangeable terms.
Another difference between manual and automatic tests is that during automatic testing, you can use a salt spray in place of a salt dip. There are several problems with ASTM B xae spray test when trying to rank the corrosion performance of automotive parts. Both are excellent browsers.
Then, assuming that sxe are actually improvements, they will revise the standard and submit it to SAE. You can run the tests manually or automatically.
Salt spray test
Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of the following 3 part repeating cycle. This is considered an out of date browser.
The reason that the ASTM B test methods do not accurately reproduce corrosion performance for auto parts is that they do not accurately reproduce the conditions in which automotive parts must exist. Once researchers have agreed on what changes to make in the test procedure, they will run a round-robin test to determine if the changes are really improvements.
SAE J is a relatively simple test to perform. In one test, they mounted panels of the standard materials on pickup trucks driven in Montreal, Quebec, and St. The test panels were mounted on the vehicles in both horizontal and vertical orientations to better represent the various surface orientations typically found in vehicle applications.
Test method SAE J2334
But we haven’t supported older browsers like IE8. Test Conditions Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of the following 3 part repeating cycle.
Inthey selected ten standard materials, including coated and uncoated parts, with a wide range of coating compositions and thicknesses. Please note The test standard summaries are for general guidance only. Other differences include the temperature changes that occur in the real world and the fact that real-world conditions include salts other than NaCl.
Though believed to be accurate at the time of writing, this may change over time. The test cycle is repeated daily, fully automatic cabinets have the option of running during the weekends or programming in a dry stage soak. Several studies have come to the conclusion that ASTM B does not provide a good test for coated aluminum alloys, or fails to predict the composition effects of aluminum-zinc alloy coatings on cold-rolled steel, or any other coatings for this matter.
When run manually, the standard allows for the fact that test personnel may not be available during weekends. So this information should not be used as a substitute for referring to a complete test standard, at an appropriate revision level. Another difference between the conditions in a salt spray test and real-world conditions is the salt concentration.