ASTM B117 is used to produce relative corrosion resistance information for specimens of metals and coated metals exposed in a standardized corrosive environment. According to ASTM International, ASTM B117, in and of itself, is not a test specification. Rather, it outlines the standard practice for operating salt spray (fog) apparatus. B117 is a document establishing the parameters and requirements for operating a salt spray test chamber. It specifies how to create and maintain the salt fog test environment so that results can be achieved consistently from lab to lab and chamber to chamber.

1. ASTM B117
Micom offers ASTM B117 accelerated corrosion testing – also known as salt
spray testing – as part of its surface finish test services.
Salt Spray Fog Testing – Uses and factors to consider:
ASTM B117 is used to produce relative corrosion resistance information for
specimens of metals and coated metals exposed in a standardized corrosive
environment.
According to ASTM International, ASTM B117, in and of itself, is not a test
specification. Rather, it outlines the standard practice for operating salt spray
(fog) apparatus. B117 is a document establishing the parameters and
requirements for operating a salt spray test chamber. It specifies how to
create and maintain the salt fog test environment so that results can be
achieved consistently from lab to lab and chamber to chamber.
ASTM B117 does not specify anything about the type of test specimen,
dimensions, shape or exposure periods to be used for a specific product, nor
does it have any requirements or guidance for the interpretation of the
results.
ASTM B117 is used in many industries, including:
Automotive (example: SAE J14563, GM 4298P…)
Paints and Coatings
Aerospace
Military (MIL-STD-810)
Among others, the following test methods call up practice ASTM B117:

2. ASTM D1654 M0140 (Nissan)
ASTM D1735 SAE 1455
ASTM D2247 GM 4298P (General Motors)
ASTM D5894 GM 9540 (General Motors)
ASTM G44 TSH1552G (Toyota)
ASTM G85 HES 6501 (Honda)
ISO 9227
This practice is used in many other standards, both in North America and
across the world. For a list of salt spray tests please see: salt spray methods
list.
The type and number of test specimens to be used, as well as the criteria for
the evaluation of the test results, will be required in the specifications
covering the product being exposed or shall be mutually agreed upon by the
parties involved.
Reasons for ASTM B117 Testing and Results
There are many different reasons for which you should conduct salt fog
testing, chief among them is determining the effect of corrosion on your
specimen. Different metals and surfaces can exhibit differing amounts of
resistance with respect to corrosion, and ASTM B117 testing will allow you to
compare this. It will also allow you to judge a surface’s tendency to corrode
when it is scratched as well as the adhesion of its coating.
The results you gain from salt spray testing will allow you to gauge how well
your metal, surface or coating can resist corrosion. By combining ASTM B117
with some of the other tests mentioned above, like ASTM D1654 and ASTM
D3359, you can also see how much scratching will affect the corrosion of your
specimen and how far corrosion creeps.
Typical Experimental Parameters for the ASTM B117 test:

3. There are numerous parameters we will want to confirm with you in order to
run a proper ASTM B117 salt spray test. These include:
Number of specimens/products: usually 1 (to be confirmed)
Specimen dimensions: 3” X 6” (Typical for flat specimen. 3D samples
can also be tested. Please specify dimensions)
Exposure duration: hours
Optional sample preparation to be specified:
Cleaning
Scribing (ASTM D1654 or other)
Edges protection if exposed
Orientation (if required please specify): While in the salt spray cabinet,
specimens shall be supported or suspended between 15 and 30 degrees
from perfectly vertical and, preferably, parallel to the principal direction
of flow of fog through the chamber, based upon the dominant surface
being tested. Samples shall be supported by their bottom or side.
Visual inspection (if specified please specify time intervals)
Post-test evaluations:
You may require interval/post-test evaluations for your sample(s).
The following test methods are most often requested
ASTM D610: Rusting on painted metal
ASTM D714: Blistering on painted metal
ASTM D1654: Rust creepage (final inspection)
ASTM D3359: Tape Adhesion
ASTM D3363: Coating Hardness
And many others…
Other related test methods:
As mentioned above, ASTM B117 is a specific accelerated aging test. For
other aging tests and additional test methods related to ASTM B117, please
see UV testing, Climatic chamber testing, Coating testing.