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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Daily checking of testing parameters is necessary to show compliance with the standards, so records shall be maintained accordingly.
They are not intended to be used for comparative testing as a means of ranking different materials relative to each other with respect to corrosion resistance or as means of predicting long-term corrosion resistance of the tested material.
What is major difference between ISO [link by ed. The test duration is variable. Hot-dip galvanizing produces zinc carbonates when exposed to a natural environment, thus protecting the coating metal and reducing nsd corrosion rate.
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.
There is a general historical consensus that larger chambers can provide a more homogeneous testing environment.
It has also been found suitable for testing anodic and organic coatings on aluminium. Remember that accelerated testing is not a proper indication of real world performance. ISO standards by standard number. The most common test for steel based materials is the Neutral 92227 Spray test often abbreviated to NSS which reflects the fact that this type of test solution is prepared to a neutral pH of 6.
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. Please note The test standard summaries are for general guidance only. Requirements are agreed between customer and manufacturer.
That’s io only way to know for sure. What do you want to test? 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. This is followed by 1.
ISO – Corrosion tests in artificial atmospheres — Salt spray tests
This page was last edited on 29 Octoberat 2927 G85 is the most popular global test standard covering modified salt spray tests. Brian Terry has directly answered your question, but please post your situation rather than an bss question so that readers can best help you. Check out our FAQs. Website design by Peter Bourne Communications. The salt spray methods are all suitable for checking that the quality of a metallic material, with or without corrosion protection, is maintained.
This acceleration 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.
These collectors are located inside the chamber, nominally at the same height as the test samples, one located close to the atomiser and one located away from the atomiser, in accordance with the positions specified in ASTM B, but also taking into account the chamber manufacturers defined work-space.
This test can be used to test the relative resistance to corrosion of aluminium alloys when exposed to a changing climate of acetic acid salt spray, followed by air drying, followed nsd high humidity, all at an elevated temperature.
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 neutral salt spray NSS test particularly applies to – metals and their alloys, – metallic coatings anodic and cathodic- conversion coatings, – anodic oxide coatings, and – organic coatings on metallic materials.
Salt spray test
ASTM G85 annex A1 — Acetic Acid Salt Spray Test non-cyclic 9227 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.
The salt solution should be prepared according to the nature of the test in accordance with Paragraph 3 of ISO and the 3 options are summarised below. Dear Brian and Davey, Thank you very much for your answers.
The longer the accelerated corrosion test, the longer the process remains out of control, and larger is the loss in the form of non-conforming 927.
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. But which, is any, accelerated test is appropriate izo on what the finish is, and what you hope to test against.