Neutral Salt Spray

The neutral salt spray (NSS) test is an accelerated corrosion test in which the sample is continuously exposed to a 5% sodium chloride fog held at a neutral pH. It is the basic and most common form of salt spray testing.

The purpose is to comparatively determine the protection duration of metal and coated surfaces in a corrosive environment, and to check coating quality and specification compliance.

• Galvanised and zinc-coated parts
• Painted and powder-coated metal surfaces
• Fasteners
• Automotive body and chassis components
• Outdoor hardware

• ISO 9227tuz sisi korozyon testi test
• ASTM B117tuz sisi (salt spray) korozyon testi test
• ASTM G85modified salt fog (cyclic) test test
• ASTM G48pitting and crevice corrosion in stainless steels test
• ISO 16701cyclic corrosion test test
• ISO 6270strength in condensation environment test
• SAE J2334cyclic laboratory corrosion testing test
• VDA 233-102cyclic corrosion testing in automotive test

Solution

5% ± 1% NaCl (by mass)

pH

6.5 – 7.2 in solution collected at 35 °C

cabin temperature

35 °C ± 2 °C

Sis toplama debisi

80 cm² yatay alanda 1,0 – 2,0 mL/saat

sample angle

15° – 25° from vertical

• Salt fog chamber
• Atomiser and humidified compressed air
• pH and conductivity meter
• Fog collection funnels

• At least three samples are generally recommended
• The surface must be cleaned and dried before the test
• Cut edges must be properly masked
• If a scribe is required for evaluation, it must be made in accordance with the standard before the test

Applied in stages such as 24, 48, 96, 240, 480, 720 or 1000 hours depending on the specification. Duration is set by the product standard or customer specification.

1. 1Samples are cleaned, marked and masked if necessary.
2. 2Chamber temperature, solution pH and fog rate are verified.
3. 3Samples are placed on the rack at the defined angle.
4. 4Fog is applied continuously for the defined duration.
5. 5Observations are recorded at interim checkpoints.
6. 6At the end of the exposure, samples are washed, dried and evaluated.

The acceptance criterion is defined in the product standard or customer specification. Common criteria are no red rust visible after a defined period, and no spread beyond a defined number of millimetres around the scribe.

Blistering, rust and scribe spread are graded by visual inspection. Results are comparative; values obtained in different chambers cannot be matched one-to-one.

• Applied standard and revision
• Chamber conditions and verification records
• Exposure duration and interim observations
• Sample description and photographs
• Assessment result

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

• Automotive OEM standards
• Coating product specifications

The section below describes the field that the Neutral Salt Spray test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

• Cyclic Corrosion
• Cyclic Corrosion
• Cyclic Corrosion
• Salt Spray
• Acetic Acid Salt Spray
• CASS
• Prohesion
• Humidity Cabinet
• SO₂ Corrosion
• Filiform Corrosion
• Galvanic Corrosion
• Intergranular Corrosion