ASTM G52-00(2006)
(Practice)Standard Practice for Exposing and Evaluating Metals and Alloys in Surface Seawater
Standard Practice for Exposing and Evaluating Metals and Alloys in Surface Seawater
SIGNIFICANCE AND USE
The procedures described herein are recommended for evaluating the corrosion or marine fouling behavior, or both, of materials exposed to quiescent or local tidal flow conditions, or both.
4.1.1 This practice is not intended to cover the influence of high seawater velocity or the behavior of materials in seawater which has been transported from its source.
4.1.2 Some aspects of this practice may be applicable to testing in tanks and troughs which are continuously provided with fresh surface seawater. Additionally, some aspects may also be applicable to deep ocean testing.
Note 1—Guide G 78 provides guidance for conducting crevice corrosion tests under controlled seawater test conditions.
While the duration of testing may be dictated by the test objectives, exposures of more than six months or one year are commonly used to minimize the effects of environmental variables associated with seasonal changes or geographic location, or both.
The procedures described are applicable for the exposure of simple test panels, welded test panels, or those configured to assess the effects of crevices, or both, such as those described in Guide G 78. In addition, they are useful for testing of actual components and fabricated assemblies.
It is prudent to include control materials with known resistance to seawater corrosion or fouling, or both, as described in Test Method D 3623.
Note 2—Materials which have been included in ASTM Worldwide Seawater Corrosivity Studies include UNS K01501 (carbon steel), UNS C70600 (90/10 CuNi) and UNS A95086 (5086-H116 Al).2 4
Note 3—In the case of evaluations of aluminum alloys, care should be exercised in the location of specimens near copper or high copper-containing alloys. In some instances, it is not sufficient to simply electrically isolate specimens to prevent bi-metallic (galvanic) corrosion; copper ions from nearby corroding copper or copper-base alloys can deposit on aluminum and accelerate its corrosion.
SCOPE
1.1 This practice covers conditions for the exposure of metals, alloys, and other materials in natural surface seawater such as those typically found in bays, harbors, channels, and so forth, as contrasted with deep ocean testing. This practice covers full immersion, tidal zone and related splash, and spray zone exposures.
1.2 This practice sets forth general procedures that should be followed in conducting seawater exposure tests so that meaningful comparisons may be made from one location to another.
1.3 This practice identifies recommended procedures for evaluating the effects of natural surface seawater on the materials exposed.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
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Designation:G52–00 (Reapproved 2006)
Standard Practice for
Exposing and Evaluating Metals and Alloys in Surface
Seawater
ThisstandardisissuedunderthefixeddesignationG52;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D3623 Test Method for TestingAntifouling Panels in Shal-
low Submergence
1.1 This practice covers conditions for the exposure of
G1 Practice for Preparing, Cleaning, and Evaluating Corro-
metals, alloys, and other materials in natural surface seawater
sion Test Specimens
such as those typically found in bays, harbors, channels, and so
2 3
G15 Terminology Relating to Corrosion and Corrosion
forth, as contrasted with deep ocean testing. This practice
Testing
covers full immersion, tidal zone and related splash, and spray
2, 4
G30 Practice for Making and Using U-Bend Stress-
zone exposures.
Corrosion Test Specimens
1.2 This practice sets forth general procedures that should
G38 Practice for Making and Using C-Ring Stress-
be followed in conducting seawater exposure tests so that
Corrosion Test Specimens
meaningful comparisons may be made from one location to
G39 Practice for Preparation and Use of Bent-Beam Stress-
another.
Corrosion Test Specimens
1.3 This practice identifies recommended procedures for
G46 Guide for Examination and Evaluation of Pitting
evaluating the effects of natural surface seawater on the
Corrosion
materials exposed.
G58 Practice for Preparation of Stress-Corrosion Test
1.4 The values stated in SI units are to be regarded as
Specimens for Weldments
standard. The values given in parentheses are for information
G78 Guide for Crevice Corrosion Testing of Iron-Base and
only.
Nickel-Base Stainless Alloys in Seawater and Other
1.5 This standard does not purport to address all of the
Chloride-Containing Aqueous Environments
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
3.1 Terms relative to this subject matter can be found in
bility of regulatory limitations prior to use.
Terminology G15.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
4.1 The procedures described herein are recommended for
evaluatingthecorrosionormarinefoulingbehavior,orboth,of
This practice is under the jurisdiction of ASTM Committee G01 on Corrosion
materialsexposedtoquiescentorlocaltidalflowconditions,or
of Metals , and is the direct responsibility of Subcommittee G01.09 on Corrosion in
both.
Natural Waters.
4.1.1 This practice is not intended to cover the influence of
Current edition approved May 1, 2006. Published May 2006. Originally
approved in 1976. Last previous edition approved in 2000 as G52–00. DOI: high seawater velocity or the behavior of materials in seawater
10.1520/G0052-00R06.
which has been transported from its source.
Kirk, W. W. and Pikul, S. J., “Seawater CorrosivityAround the World: Results
4.1.2 Some aspects of this practice may be applicable to
from Three Years of Testing,”ASTM STP 1086 Corrosion in Natural Waters, 1990,
testing in tanks and troughs which are continuously provided
pp. 3-36.
Reinhart, F. M., “Corrosion of Materials in Hydrospace,” Technical Report
with fresh surface seawater. Additionally, some aspects may
R-304, U.S. Naval Civil Engineering Laboratory, Port Hueneme, CA, December
also be applicable to deep ocean testing.
1966.
Phull, B.S., Pikul, S. J., and Kain, R. M., “Seawater Corrosivity Around the
NOTE 1—Guide G78 provides guidance for conducting crevice corro-
World: Results from Five Years of Testing,”ASTM STP 1300 Corrosion in Natural
sion tests under controlled seawater test conditions.
Waters, Vol 2, 1997, pp. 34-73.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
G52–00 (2006)
4.2 While the duration of testing may be dictated by the test 6.3 Spacing of the mounted specimens can be important. It
objectives, exposures of more than six months or one year are is desirable to have sufficient space between surfaces of test
commonly used to minimize the effects of environmental specimens to ensure that adequate water flows between them
variables associated with seasonal changes or geographic and that with long exposures the accumulated fouling will not
location, or both. block off the surface to the presence of the seawater environ-
4.3 The procedures described are applicable for the expo- ment.
sure of simple test panels, welded test panels, or those
6.4 Specimen location maps or charts should be prepared
configured to assess the effects of crevices, or both, such as
and maintained to ensure positive identification at the conclu-
those described in Guide G78. In addition, they are useful for
sion of testing. Pre-exposure photographs of assembled test
testing of actual components and fabricated assemblies.
racks are useful.
4.4 It is prudent to include control materials with known
6.5 Racks may be suspended by such materials as nylon,
resistance to seawater corrosion or fouling, or both, as de-
polyester, or polypropylene rope depending on prevailing
scribed in Test Method D3623.
conditions. Steel wire rope should be avoided.
6.5.1 For multiple year exposures, it is recommended that
NOTE 2—Materials which have been included in ASTM Worldwide
Seawater Corrosivity Studies include UNS K01501 (carbon steel), UNS theracksupportropeberesistanttodegradationbyseawateras
2, 4
C70600 (90/10 CuNi) and UNS A95086 (5086-H116 Al).
well as ultraviolet light.
NOTE 3—In the case of evaluations of aluminum alloys, care should be
6.6 Exposure racks should be suspended so that attached
exercised in the location of specimens near copper or high copper-
specimens will be oriented vertically and subjected to the full
containing alloys. In some instances, it is not sufficient to simply
effects of the seawater but free of galvanic contact with other
electrically isolate specimens to prevent bi-metallic (galvanic) corrosion;
specimens and with minimal sedimentation of silt and debris
copper ions from nearby corroding copper or copper-base alloys can
deposit on aluminum and accelerate its corrosion. on the specimen.
6.6.1 It should be recognized that in time some support
5. Test Sites
ropes may stretch due to the added mass of marine fouling. In
5.1 Test sites should be chosen at locations representative of
shallow waters, this should be taken into account to avoid
natural seawater environments where the metals or alloys to be
unwanted contact with the sea bed or bottom. In some cases,
tested may be used. Ideally, a natural seawater test site should
the added mass will also make test rack removal more difficult.
have clean, uncontaminated seawater, be in a protected loca-
NOTE 5—It should be recognized that barnacles attached to rack
tion, and have facilities for such tests as splash, tidal, and full
support ropes will create potential hazards if manual lifting is required.
immersion. Reference should be made to tropical versus other
6.7 If periodic removals are envisioned, it is recommended
conditions, and seasonal variations in temperature and in
deposition of marine growth on the test panels with a defined that different racks be utilized to support specimens for each
test period. Otherwise, marine fouling and corrosion products
“fouling season.”
5.2 Periodic observations of critical water parameters on other specimens may be disturbed and possibly affect
should be made and reported; depending on the experiment, subsequent behavior of the test material.
these might include water temperature, salinity, conductivity,
6.7.1 It is prudent to check the security of support ropes and
pH, oxygen content, and tidal flow (velocity). If there is
the presence of the test racks from time-to-time.
concern about the quality of water at the test site, it is
suggested that ammonia, hydrogen sulfide, and carbon dioxide
7. Specimens
be determined periodically using analytical chemistry proce-
7.1 When the material to be tested is in sheet form, a
dures.
nominal specimen size of 100 by 300 mm (approximately 4 by
12 in.) is recommended. Specimens may be larger or smaller to
6. Exposure Racks
suit a particular test.
6.1 Test racks should be constructed of a material that will
7.2 Odd shaped samples and assemblies comprising like or
remain intact for the entire proposed period of exposure.
dissimilar metals can also be tested. If testing materials in odd
Nickel-copper alloy 400 (UNS No. N04400) has been found to
shapes (bolts, nuts, pipes, and so forth) is desired, a means of
be an excellent material, but is not recommended for holding
supporting them in the test racks must be devised. It is
aluminum specimens. Coated aluminum racks (6061-T6 or
important that the specimens be electrically insulated from
5086-H32) also have given satisfactory service. Nonmetallic
their respective supports and from each other to prevent
racks made from reinforced plastic or treated wood might also
formation of galvanic corrosion cells. In some instances it is
be used.
not sufficient to isolate specimens electrically to prevent
6.2 Specimens must be insulated from the test racks.
corrosion of one material. For example, great care must be
Mounting devices made of porcelain and other non-metallic
exercised with aluminum specimens or racks so that they will
materials are commonly used. It should be recognized that the
not be contaminated
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