ASTM G85 annex A2

Cyclic acidified salt spray test

Can be used to test the relative resistance to corrosion of aluminium alloys when exposed to a changing climate of acetic acid salt spray, followed by air drying, followed by high humidity, all at an elevated temperature.

Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises of the following 3 part repeating cycle. 0.75 hours exposure to a continuous indirect spray of acidified (pH 2.8 to 3.0) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour. This is followed by 2.0 hours exposure to an air drying (purge) climate. This is followed by 3.25 hours exposure to a high humidity climate of 95%RH. The entire test cycle is at a constant chamber temperature of +49C. The number of cycle repeats and therefore the test duration is variable.

This test is also referred to as a MASTMAASIS test.

For further information on ASTM standards visit; www.astm.com

ASTM G85 annex A1

Acetic acid salt spray test, continuous

Can be used to test the relative resistance to corrosion of decorative chromium plating on steel and zinc based die castings, when exposed to an acetic acid salt spray climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of acidified (pH 3.1to 3.3) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable.

This test is also referred to as an ASS test.

For further information on ASTM standards visit; www.astm.com

ASTM G43

Acidified Synthetic Sea Water (Fog) Testing

Can be used to test the relative resistance to corrosion of coated or uncoated aluminium alloys and other metals, when exposed to an changing climate of acidified synthetic seawater spray, followed by a high humidity, both at an elevated temperature.

Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises of the following two part repeating cycle. 30 minutes exposure to a continuous indirect spray of acidified (pH 2.8 to 3.0) synthetic seawater solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour. This is followed by 90 minutes exposure to a high humidity climate of above 98%RH. The entire test cycle is at a constant chamber temperature of +49C (may be reduced to +24 to +35C for organically coated specimens). The number of cycle repeats and therefore the test duration is variable.

This test is also referred to as a SWAAT test.

For further information on ASTM standards visit; www.astm.com

Note; ASTM G43 has been replaced by ASTM G85 annex A3

ASTM B368

Copper Accelerated Acetic Acid Salt Spray (Fog) Testing

Can be used to test the relative resistance to corrosion of anodized aluminium and decorative copper/nickel/chromium or nickel/chromium coatings on steel and zinc based die castings, when exposed to a copper accelerated acetic acid salt spray climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of acidified (pH 3.1to 3.3) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +49C. This climate is maintained under constant steady state conditions. The test duration is variable.

This test is also referred to as a CASS test.

For further information on ASTM standards visit; www.astm.com

ASTM B287

Acetic Acid Salt Spray (Fog) Testing

Can be used to test the relative resistance to corrosion of inorganically and organically coated ferrous and non-ferrous metals, when exposed to an acetic acid salt spray climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of acidified (pH 3.1to 3.3) salt water solution, which falls-out on to the specimens at a rate of 0.75 to 2.0ml/80cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable.

This test is also referred to as an ASS test.

For further information on ASTM standards visit; www.astm.com

Note; ASTM B287 has been replaced by ASTM G85 annex A1

ASTM B117

This is the global standard for salt spray testing

Introduction

The American Society of Testing and Materials (ASTM) test B117 is one of the most widely adopted standards for salt spray testing. Its use is internationally widespread and its provisions have been frequently re-written into the national standards of other countries, and also appear in other industry specific corrosion test standards.

ASTM B117 is an excellent reference document for the salt spray practitioner, with many helpful hints and tips contained in its useful appendixes. It is also regularly updated, by an active and broad based ASTM sub-committee, so it is a standard that is continuously evolving. The suffix to the main standard number indicates the year of publication. For example, ASTM B117 – 11 indicates a 2011 publication date. Practitioners applying the ASTM B117 test standard are responsible for checking they are using the most appropriate version for their application.

For a reference guide on how to test to ASTM B117 using an Ascott chamber click the button below;

Test Methodology PDF

Test Conditions

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution (also referred to as fog or mist) which falls-out on to the specimens at a rate of 1.0 to 2.0 ml/80cm²/hour, in a chamber temperature of +35C. The pH of the salt solution fall-out should be maintained at a neutral pH ((pH 6.5 to 7.2 – this is also commonly referred to as NSS, which stands for Neutral Salt Spray). The chamber climate is maintained under constant steady state conditions. The test duration is variable.

Test Conditions ASTM B117 - Ascott Analytical - Global Manufacturer of Salt Spray Test Chambers

Method

Salt spray testing is performed by placing samples in a test chamber designed in accordance with ASTM B117 and operated in accordance with the specified conditions in ASTM B117.

The test solution to be sprayed is prepared by dissolving pure sodium chloride into pure water, in a ratio of 5% sodium chloride to 95% water, by weight. The purity for each should be as specified in ASTM B117. At the time the samples are placed into the test chamber, it should be pre-conditioned to the operating temperature of 35˚C and producing fall-out at the specified rate. The salt fog fall-out rate is verified by using a minimum of two 80cm2 funnels per salt spray atomiser, each inserted into a measuring cylinder graduated in ml. These collectors are located inside the chamber, nominally at the same height as the test samples, one located close to the atomiser and one located away from the atomiser, in accordance with the positions specified in ASTM B117, but also taking into account the chamber manufacturers defined work-space.

Typical Application

This test can be used to test the relative resistance to corrosion of coated and uncoated metallic specimens, when exposed to a salt spray climate at an elevated temperature.

The appearance of corrosion products (oxides – commonly referred to as white rust & red rust) is evaluated after a period of time. Test duration depends on the corrosion resistance of the coating; generally, the more corrosion resistant the coating is, the longer the period of testing before the appearance of oxides. For example:

Testing Zinc Nickel Coatings under ASTM B117 conditions

Prior to the appearance of white rust the approximate test duration should be c.350hrs and for red rust to appear the approximate test duration should be c.1000hrs.

The principle application of the salt spray test is therefore to enable relatively quick comparisons to be made between actual and expected corrosion resistance in terms of the time taken for oxides to appear on the samples under test. This is compared to expectations, to determine whether the test is passed or failed.

For this reason the salt spray test is most often deployed in a quality audit role, where, for example, it can be used to check the effectiveness of a production process, such as the surface coating of a metallic part. The salt spray test has very little application in predicting how materials or surface coatings will resist corrosion in the real-world, because it does not create or accelerate real-world corrosive conditions. Cyclic corrosion testing (CCT) is much more suited to this application.

If you would like further information please call our experienced team on 01827 318040 or email sales@ascott-analytical.com

AS 2331 meth.3.3

Corrosion & related property tests – copper accelerated acetic acid salt spray test

Can be used to test the relative resistance to corrosion of metallic coatings, when exposed to a copper accelerated acetic acid salt spray climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of acidified (pH 3.1to 3.3) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +50C. This climate is maintained under constant steady state conditions. The test duration is variable.

This test is also referred to as a CASS test.

Chamber volumes of less than 200 Litres are not permitted by this test standard.

For further information on Australian standards visit: www.standards.com.au

AS 2331 meth.3.2

Corrosion & related property tests – acetic acid salt spray test

Can be used to test the relative resistance to corrosion of metallic coatings, when exposed to an acetic acid salt spray climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of acidified (pH 3.1to 3.3) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable.

Chamber volumes of less than 200 Litres are not permitted by this test standard.

This test is also referred to as an ASS test.

For further information on Australian standards visit: www.standards.com.au

AS 2331 meth.3.1

Corrosion & related property tests – neutral salt spray test

Can be used to test the relative resistance to corrosion of inorganic and organic coatings on metallic substrates, when exposed to a salt spray climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of neutral (pH 6.5 to 7.2) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable.

This test is also referred to as an NSS test.

Chamber volumes of less than 200 Litres are not permitted by this test standard.

For further information on Australian standards visit: www.standards.com.au

AA-0324 (AA-P 184)

Salt spray corrosion test used to test the effectiveness of corrosion protection systems

Can be used to test the relative resistance to corrosion of metallic materials with or without temporary or permanent corrosion protection, when exposed to a salt spray climate (neutral salt spray or acetic acid salt spray or copper accelerated acetic acid salt spray) at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of neutral (pH 6.5 to 7.2) salt water solution, which falls-out on to the specimens at a rate of 30 to 40 ml/80cm²/24 hours, in a chamber temperature of +35°C or +50°C. This climate is maintained under constant steady state conditions. The test duration is variable. The chamber should not be filled to more than 50% capacity.

In all other respects this test is based upon ISO9227.

For further information on ISO standards visit; www.iso.org

Note: many ISO test standards have been harmonized with other European standards and these are now prefixed ‘EN’ (Euro Norm) or ‘** EN’ – where ** are the letters representing a European country/language code, for example ‘BS EN’ for a harmonized British standard in English language.