The test standard summaries are for general guidance only. Though believed to be accurate at the time of writing, this may change over time. So this information should not be used as a substitute for referring to a complete test standard, at an appropriate revision level.
Note: the terms salt spray, salt mist & salt fog are all in wide spread use within corrosion test standards. In this context they can be considered to be equivalent and interchangeable terms.
Accelerated corrosion test
This standard defines an accelerated corrosion test method to be used in assessing the corrosion resistance of metals in environments where there is a significant influence of chloride ions, mainly as sodium chloride from a marine source or by winter road de-icing salt. It specifies a test procedure to be used in conducting the accelerated corrosion test to simulate atmospheric corrosion conditions in a controlled way.
The one-week main test cycle is composed of two twelve-hour sub-cycles, one with controlled humidity cycling; sub-cycle 1, the other including salt solution application, sub-cycle 2.
Sub cycle 1 requires constant conditions at 35°C & 95% RH for 4 h, followed by an increase of temperature to 45°C whilst reducing the humidity to 50% over a 2 hour period. This is followed by constant conditions of 45°C & 50% RH for 4 h, together with a 2 hour period of 35°C & 95% RH. Step 1:4) Temperature decrease from 45°C to 35°C
Sub cycle 2 requires spraying with salt solution for 15 mins then keeping the samples at 35°C for 1 h 45 min whilst maintaining a set point of 95% – 99% RH in such a way that the test objects remain wet. These steps are repeated in sequence to give a total period of 6 hours. Drying at 45°C & 50% RH for a 2hour period followed by a further 2 hour period of 35°C whilst maintaining 95% RH.
This test is also referred to as a Cyclic Corrosion Test, often abbreviated to CCT.
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