ASTM G85 Annex 3 SWAAT Testing
Assured Testing Services performs Modified Salt Spray testing per ASTM G85 Annex A3, also known as the Sea Water Acetic Acid Test, or SWAAT. The ASTM G85 Annex A3 SWAAT standard only prescribes the equipment, the procedure, the electrolyte solution, and the conditions needed to maintain the cyclic acidified salt fog test environment. The conditions inside a chamber operating ASTM G85 Annex A3 SWAAT exposure are either 35C or 49C exposure temperature, with a 30 minute electrolyte spray/fog followed by a 90 minute period of humidity >98% RH using an electrolyte consisting of 42 grams/liter of ASTM D1141 Substitute Ocean Water that has been adjusted to a pH of 2.8 - 3.0 using acetic acid. The electrolyte is controlled such that its rate of condensation on the specimens is at a rate of 1.0 to 2.0 ml / 80 cm² / hour.
ASTM G85 Annex A3 Standard references other ASTM standards which Assured Testing Services maintains on its ISO 17025 scope. The other reference documents in ASTM G85 Annex A3 are listed here:
ASTM D609 “Practice for Preparation if Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related Coating Products”
ASTM D1141 “Practice for the Preparation of Substitute Ocean Water”
ASTM D1193 “Specification for Reagent Water”
ASTM D1654 “Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments”
ASTM E70 “Test Method for pH of Aqueous Solutions With the Glass Electrode”
What is the purpose of ASTM G85 SWAAT?
The purpose of the ASTM G85 Annex A3 test is to provide a controlled accelerated corrosive environment to evaluate the relative corrosion resistance of either coated or uncoated exfoliation-resistant heat treated 2000-series, 5000-series and 7000-series aluminum alloys used in the fabrication and manufacture of heat exchangers.
Assured Testing Services has multiple chambers available to expose aluminum heat exchangers and panels of typical dimensions for the ASTM G85 Annex A3 Salt Fog Test. The number of test specimens, dimensions, and duration of exposure for the test can be specified by the customer, or found on a heat exchanger drawing detail block, or in a governing specification.
When exposing parts in accordance with ASTM G85 Annex A3 Salt Fog test, sample heat exchangers or panels are submitted in replicates for validation and comparison purposes. While the specimens are in the exposure chamber, they are usually positioned in the intended in-service orientation of the heat exchanger, or in the case of panels, at an angle from 15 to 30 degrees from vertical. The duration of the test varies depending on the requirements of the specimens.
Assured Testing Services has the capability to perform complementary evaluations and preconditioning for the samples submitted, both before and after testing, such as the following:
You can download the most recent version of ASTM G85 Annex A3 Sea Water Acetic Acid Test (SWAAT) from ASTM's website at the link below: