{"id":10766,"date":"2023-08-31T10:00:32","date_gmt":"2023-08-31T08:00:32","guid":{"rendered":"https:\/\/kluthe.com\/magazin\/?p=10766"},"modified":"2026-02-23T17:20:11","modified_gmt":"2026-02-23T16:20:11","slug":"what-is-the-salt-spray-test","status":"publish","type":"post","link":"https:\/\/kluthe.com\/magazin\/en\/what-is-the-salt-spray-test\/","title":{"rendered":"What Is the Salt Spray Test?"},"content":{"rendered":"

The salt spray test in accordance with DIN EN ISO 9227 (often referred to simply as the salt spray test) is used to evaluate the quality of surface pretreatment and coatings on metals. During testing, the specimen parts are exposed to precisely defined, extreme conditions. This makes it possible to draw indirect conclusions about the effectiveness of corrosion protection. Read on to learn when a salt spray test is required and how it is carried out.<\/strong><\/p>\n

Application of DIN EN ISO 9227 (Corrosion tests in artificial atmospheres \u2013 Salt spray tests)<\/h2>\n

Corrosion preventatives<\/a> enable the use of base metals in a wide variety of components. Its effectiveness determines the service life of machines and systems, vehicles, and structures. Manufacturers of such products expect their suppliers to deliver parts that meet defined quality standards. To verify this quality, clear specifications and criteria are required. These are often summarized in the internal standards of major manufacturers. Within this framework, a salt spray test in accordance with DIN EN ISO 9227 may be required. Alternatively, this requirement \u00a0may be agreed upon contractually. The standard specifies how the test apparatus must be designed, which substances are used, and under what conditions the test is completed . All other specifications are defined by the company requesting the test from its suppliers. This includes the nature and size of the test specimens, specimen preparation, test duration, and the required results.<\/p>\n

\"Illustration:
By Ascott Analytical – Own work, CC BY-SA 4.0, https:\/\/commons.wikimedia.org\/w\/index.php?curid=42104417<\/figcaption><\/figure>\n

Artificial, corrosion-promoting atmosphere<\/h2>\n

The salt spray test is conducted in a chamber that is continuously supplied with a finely atomized salt solution via nozzles. The standard specifies three variants of the salt solution, each producing a different level of corrosive attack. The neutral salt spray test (NSS test) uses a 5% aqueous sodium chloride solution. A slightly more aggressive method is the acetic acid salt spray test (AASS test), in which acetic acid is added to the sodium chloride solution. The third variant is the copper-accelerated acetic acid salt spray test (CASS test). In this case, the solution contains sodium chloride, acetic acid, and copper(II) chloride dihydrate. DIN EN ISO 9227 specifies in detail how these solutions \u00a0should be prepared. It also defines required spray volumes, pH values, and temperatures to be used during testing. These specifications, in turn, dictate chamber equipment requirements for heating, dosing, measurement, and control.<\/p>\n

\"Chamber
Par Cjp24 , CC BY-SA 3.0, https:\/\/commons.wikimedia.org\/w\/index.php?curid=6587205<\/figcaption><\/figure>\n

Arrangement of test specimens in the chamber<\/h2>\n

To obtain reproducible results, the test specimens in a salt spray test must be exposed solely to the \u00a0corrosive action of the artificial atmosphere. Other influences, such as contact with other metals or standing moisture on the surfaces, must be excluded. For this reason, there are precise requirements regarding the materials used for the chamber and the racks holding the test specimens. The positioning of the specimens can also influence the results of the salt spray test. The following rules apply:<\/p>\n