GM9540P

Accelerated Corrosion Test (General Motors)

This is an accelerated laboratory corrosion test method that can be used to determine the corrosion resistance of automotive assemblies and components. It is said to be effective for evaluating a variety of corrosion mechanisms including general, galvanic, crevice etc. This test is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that generally comprises of the following 3 part repeating cycle (variations to this cycle are permitted depending on the type of component under test – refer to the full test standard for further guidance). 8.0 hours exposure to an ambient climate of 40 to 50%RH at +25C, during which salt solution is sprayed directly on to the test samples 4 times, for long enough to thoroughly wet them, and at intervals sufficient to allow the samples to dry between each spray. This is followed by 8.0 hours exposure to a water fog humidity climate of 100%RH at +49C. This is followed by 8.0 hours of air drying in a climate of <30%RH at +60C. The number of cycle repeats and therefore the test duration is variable.

This test is also referred to as a Cyclic Corrosion Test, often abbreviated to CCT.

For further information on General Motors standards visit; www.global.ihs.com

GMW14872

Accelerated Corrosion Test (General Motors)

This is an accelerated laboratory corrosion test method that can be used to determine the corrosion resistance of automotive assemblies and components. It is said to be effective for evaluating a variety of corrosion mechanisms including general, galvanic, crevice etc. This test is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that generally comprises of the following 3 part repeating cycle (variations to this cycle are permitted depending on the type of component under test – refer to the full test standard for further guidance). 8.0 hours exposure to an ambient climate of 40 to 50%RH at +25C, during which salt solution is sprayed directly on to the test samples 4 times, for long enough to thoroughly wet them, and at intervals sufficient to allow the samples to dry between each spray. This is followed by 8.0 hours exposure to a water fog humidity climate of 100%RH at +49C. This is followed by 8.0 hours of air drying in a climate of <30%RH at +60C. The number of cycle repeats and therefore the test duration is variable.

This test is also referred to as a Cyclic Corrosion Test, often abbreviated to CCT.

For further information on General Motors standards visit; www.global.ihs.com

GM4298P

Salt spray/mist testing(General Motors)

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

For further information on General Motors standards visit; www.global.ihs.com

GM4465P

Humidity Test(General Motors)

Can be used to test coated specimens by exposing them to water fog at an elevated temperature, using apparatus similar to that used for salt spray testing to ASTM B117.

Test specimens are placed in an enclosed chamber that meets the apparatus requirements of ASTM B117. Here they are exposed to a continuous indirect spray water, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +38C and a humidity of 100%RH. This climate is maintained under constant steady state conditions. The test duration is variable.

For further information on General Motors standards visit; www.global.ihs.com