Corrosion Testing

Corrosion is a form of material degradation that happens when material interacts with its environment. It can happen in any form and cause a range of material alteration from mechanical damage through changes in physical properties to changes in physical appearance.

From pitting (creating small holes in the metal) and blistering (showing loss of adhesion between coating and base object), to intergranular corrosion (IGC) in specific zones of the material, corrosion resistance is affected by numerous external factors such as temperature, water, humidity or moisture, acids and salts, or even contact with other materials.

Since a large number of factors affect corrosion behavior and corrosion resistance, there is no universal corrosion test. You can rely on our many years of experience in corrosion testing. We provide different exposure tests, including salt spray tests in our accredited corrosion testing laboratories around the world. Our corrosion testing services are in accordance with all relevant and applicable standards. You can find a detailed list of the most important codes and standards under the Legal Background tab .

Whether metallic products or stainless steel, TÜV Rheinland offers comprehensive testing solutions. We enable tube manufacturers or welding industry professionals to determine the quality and assess corrosion resistance of their materials even within the manufacturing process.

Using the corrosion testing services from TÜV Rheinland, you benefit from:

• Integral evaluation of the corrosion resistance of stainless steels and related materials.
• A high capacity corrosion testing laboratory with fast response time.
• Testing methods adapted to the type of material and your manufacturing process.
• Tests conducted in accordance with applicable standards or your specifications.
• TÜV Rheinland’s accredited corrosion testing laboratories and years of experience in corrosion analysis.

Please contact us to learn more about how our corrosion testing services can benefit your company.

There are different factors that affect the corrosion rate of a material. These include humidity, temperature, air pollution, water quality, acids, salts, or contact between dissimilar metals. Our accredited corrosion testing laboratory can therefore provide different exposure tests to examine the corrosion resistance properties of your material.

To test corrosion resistance of material in artificial atmospheres we observe the following steps:

1. Our experts first review the tested sample’s documentation and inspect its appearance before exposure.

2. We then proceed to sample exposure, taking into account the specific test parameters applicable.

3. Finally, we review the sample’s appearance after exposure.

4. Documentation includes the corrosion position, its extent as well as the presence of pitting, rust or blistering.

The salt spray test is a standardized exposure test in artificial atmosphere. This test method is used to evaluate the corrosion resistance of coated samples by generating a corrosive attack.

To test corrosion resistance of material in corrosive solutions, the tested sample first has to undergo mechanical and/or chemical preparation – sandpapering or etching for instance. We then proceed to sample exposure in the corrosive solution, taking into account the specific test parameters applicable. Finally, we determine the material’s loss in mass through sample comparison weighing before and after exposure. Our experts also conduct visual inspection of the surface, looking for cracks, pitting, blistering or intergranular corrosion attacks.

Listed below please find some of the most relevant regulations, codes and standards related to corrosion testing.

• ISO 3651-1: This standard specifies the method of the determination of resistance to intergranular corrosion in austenitic and ferritic-austenitic (duplex) stainless steels.
• ISO 3651-2: Determination of resistance to intergranular corrosion of ferritic, austenitic and ferritic-austenitic (duplex) stainless steels.
• ASTM A262: This standard covers the practices for detecting susceptibility to intergranular attack in austenitic stainless steels.
• ASTM G48: This standard describes test methods for pitting and crevice corrosion resistance in stainless steels and related alloys by use of ferric chloride solution.
• SEP 1877: Test of the resistance of high-alloy, corrosion-proof materials against intercrystalline corrosion.
• ISO 9227: “Corrosion tests in artificial atmospheres”. This standard specifies the methods and the procedure to be used in conducting the neutral salt spray (NSS), acetic acid salt spray (AASS) and copper-accelerated acetic acid salt spray (CASS) tests for assessment of the corrosion resistance of metallic materials
• ISO 6270-2: “Paints and varnishes: determination of resistance to humidity part”. This standard describes the procedure for exposing test specimens in condensation-water atmospheres.