ISO 9227 Salt Spray Test-Salt Fog Test Chamber
Salt spray testing is particularly suitable for detecting discontinuities, such as pores and other defects, in certain metallic, organic, anodized and conversion coatings.
NSS testing is particularly suitable for:
Metals and their alloys;
Metallic coatings (anodic and cathodic);
Conversion coatings;
Anodic oxide coatings;
Organic coatings on metallic materials.
ISO 9227 salt spray corrosion test methods
The NSS test is a test method for atomizing about 5% neutral sodium chloride solution in a controlled environment.
The AASS test is a test method in which approximately 5% sodium chloride solution is acidified with the addition of acetic acid and atomized in a controlled environment.
The CASS test is a test method for atomizing a solution of about 5% sodium chloride in a controlled environment that is acidified by the addition of acetic acid and the addition of copper (II) chloride.
Experimental parameters of the test
| Test method item | Neutral salt spray | Acetic acid salt spray | Copper-accelerated acetic acid salt spray |
| (NSS) | (AASS) | (CASS) | |
| Temperature | 35C ± 2 C | 35C ± 2 C | 50C ± 2 C |
| Average collection rate for a horizontal collecting area of 80 cm2 | 1,5 mL/h ± 0,5 mL/h | ||
| Concentration of sodium chloride (collected sodium) | 50 g/L ± 5 g/L | ||
| pH (collected solution) | 6,5 to 7,2 | 3,1 to 3,3 | A discrepancy has been found for the pH of this test method. Section 3.2.4 states that the pH shall be 6,5 to 7,2 while table 2 states that it shall be 3,1 to 3,3. |
| Number of test specimens | To be specified, typically 1 | ||
| Shape and size of specimens | To be specified, typically 75 x 150 mm | ||
| Arrangement of the test specimens | The specimen must be flat and placed in the cabinet facing upwards at an angle as close as possible to 20 o to the vertical. This angle shall, in all cases, be within the limits 15 o to 25 o. | ||
| Duration of tests | To be specified. Typical exposure periods are 2 h, 6 h, 24 h, 48 h, 96h, 168 h, 240 h, 480 h, 720 h, 1 000 h and | ||
ISO 9227 evaluation of results
Many different criteria for the evaluation of the test results may be applied to meet particular requirements, for example
- appearance after the test;
- appearance after removing superficial corrosion products;
- number and distribution or corrosion defects (i.e. pits, cracks, blisters, rusting or creep from scratches in the case of organic coatings) to be assessed by methods described in Iso 8993, ISO 8994 or ISO 10289 and, for organic coatings, in ISO 4628-1, ISO 4628-2, ISO 4628-3, ISO 4628-4, ISO 4628-5 and ISO 4628-8
- time elapsed before the appearance of the first signs of corrosion;
- change in mass;
- alteration revealed by micrographic examination;
- change in mechanical properties;
- colorimetry.
Salt Fog Test Chamber
JOEO is a leading manufacturer of salt fog test chamber in China, meeting the test standards: ASTM B117, ISO9227,mil std 810, IEC 60068, JIS Z 2371 ect, the chamber size can reach walking size, and has a wide temperature range of salt spray continuous or periodic cycles. The test is typically conducted for 500 to 1,000 hours to determine the corrosion properties of a metal or composite.
If you have any questions about the ISO 9227 test, we invite you to contact us immediately. We will be happy to answer your questions and help you with your custom testing requirements.
