Salt spray test

There are a number of corrosion tests that may be used to determine the long-term durability of protective coatings. However, the focus of this article is on the Salt spray test. This test creates a corrosive attack on coated samples in order to determine the coating’s fitness for application. This article will help you learn how to utilize and apply the salt spray test.

LISUN’s Salt spray test chamber

The Salt spray test Chamber is used to conduct salt spray corrosive tests on components, parts, electronic and electrical components, metal materials, and industrial products. The salt fog test chamber complies with the following specifications:
IEC60068-2-11 (GB/T2423 .17), GB/T10125, GB/T1771, ISO9227, ASTM-B117, GB/T2423-18, QBT3826, QBT3827, IEC 60068-2-52, ASTM-B368, MIL-STD-202, EIA-364-26 , GJB150, DIN50021-75, ISO3768.

Salt spray test

The Salt spray test is a standardized test that compares the relative corrosion resistance of different coatings under conditions that attempt to mimic the true corrosive environment. However, this induced corrosion is accelerated or completed in a short period of time. For example, this test is commonly used to compare the corrosion rates of a ruspert coating and a black oxide coating.

In this case, if the test shows that the ruspert coating lasts for 800 hours while the black oxide coating lasts for 24 to 96 hours, it implies that the ruspert coating is more durable than the black oxide coating in the same corrosive environment. However, it may be a mistake to rely solely on the Salt spray test for comparison and to draw conclusions about which coating is superior without first thoroughly understanding the behavior of different coatings in real-world environments. This will be covered in greater detail later in this article.

Understanding Salt spray test

How is Salt spray testing done? Typically, this test is performed in accordance with the ASTM B117 or ISO 9227 testing procedures. The samples being compared are placed in an enclosed chamber and then exposed to a thick metal fog that simulates severely corrosive conditions. The The test employs a sodium chloride solution with a pH range of 6.5 to 7.2.

This test typically lasts 8 to 3,000 hours. Though, as previously stated, there are a variety of other corrosion tests, the salt spray test is very common. However, experts are divided on how closely it reflects real-life conditions. Some experts, for example, question the test’s suitability because it does not involve exposure to salt chemicals.

There are a number of compelling reasons to conduct a salt spray test, the most important of which is to determine how corrosion will affect your specimen. Different surfaces and metals can have different levels of corrosion resistance, and this test allows you to compare them. Furthermore, the test allows you to determine a surface’s proclivity to corrode in the event that it is scratched, as well as assess the stickiness of the coating.

The following are a few examples of relative salt spray test results
• Black Oxide – Samples show corrosion after 24 to 96 hours
• Ruspert Coating (200 & 300) – Samples show no traces of red rust after 1000 hours
• Powder Coating – Samples can last up to 500 hours before rusting
• Stainless steel (304 & 316) – Results vary depending on the finish However, after 1000 hours, the majority of samples in this category show almost no corrosion.

Salt spray test hours

It should be noted that, contrary to popular belief, the Salt spray test, like other corrosion tests, does not show any correlation. The test for X hours does not imply that the coating will resist corrosion for a certain number of years. This is due to the fact that rust takes years to form in real-life situations. As a result, the best course of action is to use this test solely as a predictor of real-world outcomes.

To fully comprehend the preceding, the Salt spray test should be viewed as a quality-control measure used to ensure that process control is on track and accurate. In other words, the results of this testing are not indicative of real-world outcomes. To give you an example, if you know that zinc plating lasts 96 hours and powder coating lasts 500 hours but your test sample doesn’t, it means that something went wrong with our process.

On the same note, you should proceed with caution if you draw the conclusion from these figures that powder coating is more resistant than zinc plating. Such an inference would be misleading because, as previously stated, spray salt rating is not a predictor of which coating will outperform the other in the real world.

Consider hot dip galvanizing, which can last between 75 and 100 years with no maintenance. However, it fails miserably in this test. This is due to the fact that its actual endurance in the real world is dependent on other factors such as the gradual formation of a glassy skin of corrosion products, which does not form in this type of test.

In a nutshell, the Salt spray test is a popular method for determining the durability of protective coatings. Despite the fact that it is a standardized test, the results have no correlation with the number of years the coating can last before showing signs of corrosion.

The salt spray test is the most common corrosion test used by users of high corrosion-resistant materials. This test has numerous advantages. The fact that it is multi-lateral means that it can be used on bare material, painted material, and noble or sacrificial coating.

The test duration is much shorter than in real life conditions, allowing for cost savings when testing material durability and quality. Because this method is widely used, it has a limited number of techniques, making its application simple and common. This test can also be used to perform a combined surface finish and material test.

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

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