Facilities
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Atmospheric Exposure Test Facility
The Atmospheric
Exposure Site (Kennedy Space Center, FL) was established in the 1960s and
has been cited as the most corrosive atmospheric corrosion test site in
the United States. It is located at latitude 28.59406°N, longitude 80.58283°W,
and approximately 100 feet from the high tide line. Over the years
thousands of coated test panels, stress corrosion cracking specimens, and
commercially produced components have been evaluated in the high salt,
high humidity, high UV Florida seacoast environment.
Corrosion
rates of carbon steel calibrating
specimens at various locations*
|
Location |
Type Of
Environment |
µm/yr |
Corrosion rate
(a) mils/yr |
Esquimalt,
Vancouver Island, BC, Canada |
Rural marine |
13 |
0.5 |
Pittsburgh, PA |
Industrial |
30 |
1.2 |
Cleveland, OH |
Industrial |
38 |
1.5 |
Limon Bay,
Panama, CZ |
Tropical marine |
61 |
2.4 |
East Chicago,
IL |
Industrial |
84 |
3.3 |
Brazos River,
TX |
Industrial
marine |
94 |
3.7 |
Daytona Beach,
FL |
Marine |
295 |
11.6 |
Pont Reyes, CA |
Marine |
500 |
19.7 |
Kure Beach, NC
(80 ft. from ocean) |
Marine |
533 |
21.0 |
Galeta Point
Beach, Panama CZ |
Marine |
686 |
27.0 |
Kennedy
Space Center, FL (beach) |
Marine |
1070 |
42.0 |
(a)
Two-year average
* Data extracted from: S.
Coburn, Atmospheric Corrosion, in Metals Handbook, 9th ed, Vol. 1,
Properties and Selection, Carbon Steels, American Society for
Metals, Metals Park, Ohio, 1978, p.720 |
The site has approximately 600
feet of front row exposure for atmospheric corrosion specimens. Many types
of test samples can be accommodated, including standard size test coupons
(4"X 6"), stress corrosion cracking specimens, and full-scale
test articles. These experiments can be performed in either a boldly
exposed or sheltered configuration. Both power and data connections are
available within the site to power test articles and record onboard data
instrumentation outputs.
Corrosivity
KSC has the highest corrosivity
of any test site in the continental United States. This means samples
exposed at this site will weather or degrade at rates far in excess of the
rates experienced at other sites. The chart below shows the relationship
between salt deposition, corrosion, and distance from the ocean.
J.D. Morrison, Report on the
Relative Corrosivity of
Atmospheres at Various Distances from the Seacoast,
NASA-KSC Report MTB 099-74
Continuous Atmospheric Condition Monitoring
Continuous on-line
monitoring of the following parameters is recorded and can be transmitted
to any location:
- Temperature
- Humidity
- Wind speed and direction
- Rainfall
measured in 20 minute increments
recorded and archived by day, month, year, etc.
- Total incident solar
radiation
- UVB radiation.
Examples
of Exposure Results at the Atmospheric Site
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The left photo
shows exfoliation corrosion of carbon steel after filiform corrosion
undercuts a protective coating. The original flat panel was scribed
with an X to expose the underlying metal and to test the
protectiveness of the coating at holidays in the coating. |
The photo to
the right shows corrosion of aluminum panels after the coating
debonds from the aluminum substrate. |
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The photo to
the left shows exfoliation corrosion of 2024-T6 aluminum after years
of exposure at the Beach Corrosion Test Site. The corrosion pattern
is caused by the expansion of corrosion products between the primary
aluminum crystals. |
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