ASTM G44 Salt Spray Corrosion Test-Salt Spray Test Apparatus

The ASTM G44 Salt Spray Corrosion Test covers the procedure for performing alternating immersion stress corrosion tests in 3.5% sodium chloride (NaCI).  ASTM G44 salt spray corrosion test method is primarily used for testing aluminum and ferrous alloys, but can also be used for other metals that are sensitive to chloride ions.

ASTM G44 Uses and considerations

ASTM G44 salt spray corrosion testing is more rigorous than ASTM B117 salt spray testing. It is suitable for alloy development and applications where the alternate immersion test is used as a control test for the quality of successive batches of the same material, which involves taking a sample and then dipping it into a sodium chloride solution and extracting it with the aid of a robotic arm. The alternate soaking test used a 1-hour cycle, which consisted of soaking in an aqueous solution of 3.5% sodium chloride (NaCI) for 10 minutes, followed by soaking in the solution for 50 minutes, during which time the sample was allowed to dry. This 1-hour cycle lasts 24 hours/day for the total number of days recommended for the particular alloy being tested. Normal. Exposure times for aluminum and iron alloys range from 20 to 90 days or more, depending on the alloy's resistance to saltwater corrosion.

Salt Spray Test Apparatus

1.Cycle Method - Any suitable mechanism can be used to complete the immersion part of the cycle, as long as it reaches the prescribed immersion and removal rates and the device is constructed of suitable inert materials. The usual soaking methods are:
1.1 Specimens placed on a movable rack that is periodically lowered into a stationary tank containing the solution.
1.2 Specimens placed on a hexagonal Ferris wheel arrangement which rotates every 10 min through 600 and, thereby, passes the specimens through a stationary tank of solution. Use of a Ferris wheel continuously rotating at a rate of 1 revolution per hour is not recommended for very large specimens for which the rate of immersion would be slower than that specified in 2.
1.3 Specimens placed in a stationary tray open to the atmosphere and having the solution moved by air pressure nonmetallic pump, or gravity drain from a reservoir to the tray.

2.Rate of Immersion-The rate of immersion and removal of the specimens from the solution should be as rapid as possible without jarring them. For purposes of standardization, an arbitrary limit shall be adopted such that no more than 2 min elapse from the time the first portion of any specimen is covered (or uncovered) until it is fully covered (or uncovered) by solution.

3 Materials of Construction:
3.1 Materials of construction that come in contact with the salt solution shall be such that they are not affected by the corrodent to an extent that they can cause contamination of the solution and change its corrosiveness.
3.2 Use of inert plastics or glass is recommended where feasible.
3.3 Metallic materials of construction should be selected from alloys that are recommended for marine use and of the same general type as the metals being tested. Preferably, all metal parts should be protected with a suitable corrosionresistant coating that also satisfies paragraph 3.1.

Solution Conditions

Additional information related to ASTM G44

If you are looking for more information about corrosion testing, we invite you to visit the following resources on our website:
· Learn more about ASTM B117 testing
· Learn more about MIL STD 810G testing 
· Learn more about coating MIL-DTL-5541F testing 
· Learn about our salt spray test apparatus
If you have any questions about aluminum and ferroalloy testing, you are welcome to contact us immediately. We are happy to answer your questions about ASTM G44.