ACCELERATED LIFE TESTING

SWAAT Testing -- Acidified Synthetic Sea Water (Fog) Test, ASTM G85, Annex 3

Touchstone has several salt spray cabinets and can conduct both standard and customized testing.

Test background and description:

SWAAT Testing is performed according to ASTM G 85, Annex A3. It is performed in a salt fog cabinet. A 5% solution of synthetic sea water is made up from sea salt (instead of food grade salt). The solution is acidified with acetic acid to a pH between 2.8 and 3.0 and atomized as a fog into the heated cabinet maintained at 120° F (49° C). Cabinets are equipped with a timing device to effect a cycle typically consisting of a 30-min. spray followed by a 90-min. soak period at above 98% relative humidity. Cabinets can also be operated at 95° F (35° C), or other temperatures if required.

This test can be used to determine time to perforation primarily on aluminum alloy brazing sheet used to manufacture heat exchangers, or even complete heat exchangers under pressure, or other parts. It can also applicable to determine how varying heat treatment parameters affect corrosion behavior. Testing of organic coatings on metal substrates can also be conducted, where a lower temperature is typically used to prevent paint blistering.

This test was originally published as ASTM G43, prior to the current ASTM G 85, Annex A3. SWAAT stands for Sea Water Acetic Acid Test.

Sample preparation and placement:

Touchstone has tested both coupons and entire components for automotive, aerospace, and other industries. If you are interested in coupon testing, we can prepare and coat the edges, to eliminate edge corrosion.

Samples are typically placed at a 15-30 degree angle from vertical, however components for aerospace or automotive are generally oriented in the "as used" position. Samples are located so condensate from one sample does not drip onto another sample.

Test time ranges from 24 to thousands of hours, usually in 24 hour increments. We can recommend a test length, and also an inspection frequency. We have several cabinets that can run different salt spray tests.

Additional related tests and analysis:

In addition to ASTM G85, Annex 3, Touchstone performs other corrosion testing such as CASS testing. We can also conduct tests to third party specifications in the aerospace, military, or automotive areas such as GM SWAAT corrosion testing specification GME 60 213.

Consulting on corrosion problems is also available. Our light microscopy, metallography, and mechanical testing laboratories can provide a full suite of tests to support your material characterization program.

Index of Accelerated Life Testing