ISO NSS. adv. auto technology banner. A discussion started in but continuing through Q. We have a customer, that we supply some zinc. Information to the interpretation of the result. The salt spray test is done according to DIN EN ISO (NSS). The paint thickness is measured. 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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Hi Sergio, ASTM B does not address corrosion behavior of test specimens, but describes the parameters for conducting a salt spray test.
Brian Terry has directly answered your question, but please post your situation rather than an abstract question so that readers can best help you. The test duration is variable. You will then need to talk to your customer about the possibility of using one specification in lieu of the other.
Monday to Friday – The most appropriate test cycle and spray solutions are to be agreed between parties. We have a customer, that we supply some zinc electroplated mechanical components to. But which, is any, accelerated test is appropriate depends on what the finish is, and what you hope to test against. Results are represented generally as testing hours in NSS without appearance of corrosion products e. So I will start with benchmark with these two standards.
The salt spray tests are particularly useful for detecting discontinuities, such as pores and other defects, in certain metallic, organic, anodic oxide and conversion coatings.
The principle application of the salt spray test is therefore enabling nsd comparisons to be made between actual and expected corrosion resistance. March 16, A. Other test solutions have other chemicals added including acetic acid often abbreviated to ASS and acetic acid with copper chloride often abbreviated to CASS each one chosen for the evaluation of decorative coatings, such as electroplated copper-nickel-chromium, electroplated copper-nickel or anodized aluminum.
Electroplated zinc-nickel steel parts can last more than hours in NSS test without red rust or 48 hours in CASS test without red rust Requirements are established in test duration hours and coatings shall comply with minimum testing periods.
There is a general historical consensus that larger chambers can provide a more homogeneous testing environment. If there is a minimum volume required by a particular salt spray test standard, this will be clearly stated and should be complied with. However, these testing standards neither provide information of testing periods for the coatings to be evaluated, nor the appearance of corrosion products in form of salts.
ISO – Corrosion tests in artificial atmospheres — Salt spray tests
Hot-dip galvanizing produces zinc carbonates when exposed to a natural environment, thus protecting the coating metal and reducing the corrosion rate.
Retrieved from ” https: Test specimens are placed in an enclosed chamber, and exposed to a changing climate dinn comprises the following 2 part repeating cycle.
ASTM G85 annex A1 — Acetic Acid Salt Spray Test non-cyclic This test can be used to determine the relative resistance to corrosion of decorative chromium plating on steel and zinc based die casting when exposed to an acetic acid salt spray climate at an elevated temperature.
Corrosion tests and standards: The neutral salt spray NSS test particularly applies to 9227 metals and their alloys, – metallic coatings anodic and cathodic- conversion coatings, – anodic oxide coatings, and – organic coatings on metallic materials. The number of cycle repeats and therefore the test duration is variable. Views Read Edit View history.
Salt spray test
The first climate cycle comprises a continuous indirect spray of neutral pH 6. What do you want to test? Painted surfaces with an underlying hot-dip galvanized coating can be tested according to this method.
Chamber volumes vary from supplier to supplier. The appearance of corrosion products rust or other oxides is evaluated after a pre-determined period of time. From beautiful Pine Beach New Jersey: A personal good afternoon to all, I am Jose of Curitiba, I am a painting inspector, I am a specialist in the area of Salt Spray, and have a problem and knowing of the competence of all readers in corrosion, perhaps they can help me.
Is it possible to reduce test duration by some accelerated Testing? I suggest that you send some parts out for testing according to the ISO standard to see if they meet the spec. Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises the following 3 part repeating cycle.
But benchmarking performance is something altogether different.
Testing cabinets are manufactured according to the specified requirements here. 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. From Wikipedia, the free encyclopedia. The salt spray test is one of the most widespread and long established corrosion tests. Cyclic corrosion testing is better suited to this. Regards, Ted Mooney, P. Most Salt Spray Chambers today are being used NOT to predict the corrosion resistance of a coating, but to maintain coating processes such as pre-treatment and painting, electroplating, galvanizing, and the like, on isso comparative basis.
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 dim to low cost and quick results. It’s not possible ns diagnose a finishing problem or the hazards of an operation via these pages. George Gorecki – Naperville, Illinois A. What is major difference between ISO [link by ed.
Different coatings have 99227 behavior in salt dkn test and consequently, test duration will differ from one type of coating to another. For example, a typical electroplated zinc and yellow passivated steel part lasts 96 hours in salt spray test without white rust. 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. The second climate cycle comprises 0.