MIL-STD-750 method 1046

Method 1046.3: Salt Spray (Corrosion)

This MIL standard had been revised and re-issued several times, with each issue being designated a new sequential suffix letter, which appears after the main standard number. With each revision the method number specific to this particular test may have changed, but the method itself is generally as follows:

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, which falls-out on to the specimens at a rate that deposits 0.5 to 3.0/80cm²/hour based on an average run of at least 16 hours, in a chamber temperature of +35°C +1.1°C, –1.7°C. This climate is maintained under constant steady state conditions. The test duration is either 48 hours or 96 hours.

Note that a 24hr drying period at 40°C is required at the completion of the test.

For further information on US Dept of Defence MIL standards visit; www.nssn.org

MIL-STD-202

Electronic & electrical component parts: Salt Spray (Corrosion)

This MIL standard had been revised and re-issued several times, with each issue being designated a new sequential suffix letter, which appears after the main standard number. With each revision the method number specific to this particular test may have changed, but the method itself is generally as follows:

Can be used to test the relative resistance to corrosion of coated and uncoated specimens, 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 0.5 to 3.0ml/80cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable.

For further information on US Dept of Defence MIL standards visit; www.nssn.org

JNS 30.16.03

Test method for resistance to salt fog (Jaguar)

JNS 30.16.03

This Jaguar automotive test standard is based upon test standard ASTM B117. Please see elsewhere in this document for details of ASTM B117.

JIS Z 2371

Methods of neutral salt spray testing

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.

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.

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

This test is also referred to as an NSS test.

For further information on Japanese JIS standards visit; www.jsa.or.jp/default_english.asp

JIS H 8502 M3

Methods of corrosion resistance test for metallic coatings

Can be used to test the relative resistance to corrosion of electro-plated coatings, when exposed to different corrosive atmospheres, as follows:

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

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, acidified (pH 3.1to 3.3) by the addition of acetic acid, 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

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, with copper chloride added and acidified (pH 3.0 to 3.2) by the addition of acetic acid, 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

Test specimens are coated with Corrodkote mud, which is applied to the surface of the samples and allowed to dry. Then the samples are placed in a controlled climate of +38C and 80 to 90%RH (non condensing) and allowed to stand for 16 hours (1 cycle). For further cycles the samples are cleaned and fresh Corrodkote is applied.

Test specimens are exposed to a controlled climate of +40C and 90%RH and SO2 gas in a concentration of either 25ppm or 1000ppm.

Chamber volumes of less than 200 Litres are not permitted by JIS H 8502.

For further information on Japanese JIS standards visit; www.jsa.or.jp/default_english.asp

JIS H 8502 M2

Methods of corrosion resistance test for metallic coatings

Can be used to test the relative resistance to corrosion of electro-plated coatings, when exposed to different corrosive atmospheres, as follows:

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

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, acidified (pH 3.1to 3.3) by the addition of acetic acid, 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

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, with copper chloride added and acidified (pH 3.0 to 3.2) by the addition of acetic acid, 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

Test specimens are coated with Corrodkote mud, which is applied to the surface of the samples and allowed to dry. Then the samples are placed in a controlled climate of +38C and 80 to 90%RH (non condensing) and allowed to stand for 16 hours (1 cycle). For further cycles the samples are cleaned and fresh Corrodkote is applied.

Test specimens are exposed to a controlled climate of +40C and 90%RH and SO2 gas in a concentration of either 25ppm or 1000ppm.

Chamber volumes of less than 200 Litres are not permitted by JIS H 8502.

For further information on Japanese JIS standards visit; www.jsa.or.jp/default_english.asp

JIS H 8502 M1

Methods of corrosion resistance test for metallic coatings

Can be used to test the relative resistance to corrosion of electro-plated coatings, when exposed to different corrosive atmospheres, as follows:

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

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, acidified (pH 3.1to 3.3) by the addition of acetic acid, 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

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, with copper chloride added and acidified (pH 3.0 to 3.2) by the addition of acetic acid, 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

Test specimens are coated with Corrodkote mud, which is applied to the surface of the samples and allowed to dry. Then the samples are placed in a controlled climate of +38C and 80 to 90%RH (non condensing) and allowed to stand for 16 hours (1 cycle). For further cycles the samples are cleaned and fresh Corrodkote is applied.

Test specimens are exposed to a controlled climate of +40C and 90%RH and SO2 gas in a concentration of either 25ppm or 1000ppm.

Chamber volumes of less than 200 Litres are not permitted by JIS H 8502.

For further information on Japanese JIS standards visit; www.jsa.or.jp/default_english.asp

ISO 9227

The European derivative of ASTM B117, the global standard for salt spray testing

Introduction

The salt spray test developed by the American Society of Testing and Materials (ASTM) test B117 is one of the most widely adopted standards. Its use is international and its provisions have been re-written into the national standards of other countries, ISO 9227 is the European derivative of this standard.

ISO9227 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, so it is a standard that is continuously evolving. Practitioners applying the ISO 9227 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 this standard 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 chamber climate is maintained under constant steady state conditions. The test duration is variable.

NSS & AASS

ISO 9227 Standards - Ascott Analytical, the global leader in the design and manufacture of salt spray test chambers. UK - Worldwide

CASS

ISO 9227 Standards - Ascott Analytical, the global leader in the design and manufacture of salt spray test chambers. UK - Worldwide

Method

Salt spray testing is performed by placing samples in a test chamber designed in accordance with Paragraph 4 (Apparatus) of ISO 9227 and operated in accordance with Paragraph 8 (Operating conditions) of ISO 9227.

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.

The salt solution should be prepared according to the nature of the test in accordance with Paragraph 3 of ISO 9227 and the 3 options are summarised below;

NSS (Neutral Salt Spray) – The pH of the salt solution fall-out should be maintained at a neutral pH (pH 6.5 to 7.2)

AASS – A sufficient amount of glacial acetic acid should be added to the salt solution (should modify the pH to 3.1 to 3.3)

CASS – A sufficient amount fo copper chloride dihydrate should be added to the salt solution to produce a concentration of 0.26g/l +/- 0.02g/l

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

The ISO 9227 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.

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

ISO 7253

Paints & varnishes – determination of resistance to neutral salt spray (fog)

Can be used to test the relative resistance to corrosion of paints and varnishes, when exposed to a salt spray (fog) 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 2.5ml/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 400 Litres are not permitted by this test standard.

This test is also referred to as a Neutral Salt Spray or NSS test.

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.

ISO 3770

Corrosion testing of metallic coatings – 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.

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

This test is also referred to as a CASS test.

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

Note; ISO 3770 has been replaced by ISO 9227.