ASTM G52-00(2011)
(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
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: G52 − 00 (Reapproved 2011)
Standard Practice for
Exposing and Evaluating Metals and Alloys in Surface
Seawater
This standard is issued under the fixed designation G52; the number immediately following the designation indicates the year of original
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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers conditions for the exposure of
D3623 Test Method for Testing Antifouling Panels in Shal-
metals, alloys, and other materials in natural surface seawater
low Submergence
such as those typically found in bays, harbors, channels, and so
2 3 G1 Practice for Preparing, Cleaning, and Evaluating Corro-
forth, as contrasted with deep ocean testing. This practice
sion Test Specimens
covers full immersion, tidal zone and related splash, and spray
G15 Terminology Relating to Corrosion and Corrosion Test-
2,4
zone exposures.
ing (Withdrawn 2010)
1.2 This practice sets forth general procedures that should G30 Practice for Making and Using U-Bend Stress-
Corrosion Test Specimens
be followed in conducting seawater exposure tests so that
G38 Practice for Making and Using C-Ring Stress-
meaningful comparisons may be made from one location to
Corrosion Test Specimens
another.
G39 Practice for Preparation and Use of Bent-Beam Stress-
1.3 This practice identifies recommended procedures for
Corrosion Test Specimens
evaluating the effects of natural surface seawater on the
G46 Guide for Examination and Evaluation of Pitting Cor-
materials exposed.
rosion
G58 Practice for Preparation of Stress-Corrosion Test Speci-
1.4 The values stated in SI units are to be regarded as
mens 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
3. Terminology
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.1 Terms relative to this subject matter can be found in
Terminology G15.
bility of regulatory limitations prior to use.
4. Significance and Use
4.1 The procedures described herein are recommended for
evaluating the corrosion or marine fouling behavior, or both, of
materialsexposedtoquiescentorlocaltidalflowconditions,or
both.
This practice is under the jurisdiction of ASTM Committee G01 on Corrosion
4.1.1 This practice is not intended to cover the influence of
of Metals, and is the direct responsibility of Subcommittee G01.09 on Corrosion in
Natural Waters. high seawater velocity or the behavior of materials in seawater
Current edition approved Nov. 1, 2011. Published December 2011. Originally
which has been transported from its source.
approved in 1976. Last previous edition approved in 2006 as G52–00 (2006). DOI:
4.1.2 Some aspects of this practice may be applicable to
10.1520/G0052-00R11.
testing in tanks and troughs which are continuously provided
Kirk, W. W., and Pikul, S. J., Seawater Corrosivity Around the World: Results
from Three Years of Testing, ASTM STP 1086 Corrosion in Natural Waters, 1990 ,
pp. 3-36.
3 5
Reinhart, F. M., “Corrosion of Materials in Hydrospace,” Technical Report For referenced ASTM standards, visit the ASTM website, www.astm.org, or
R-304, U.S. Naval Civil Engineering Laboratory, Port Hueneme, CA, December contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
1966. Standards volume information, refer to the standard’s Document Summary page on
Phull, B. S., Pikul, S. J., and Kain, R. M., Seawater Corrosivity Around the the ASTM website.
World: Results from Five Years of Testing, ASTM STP 1300 Corrosion in Natural The last approved version of this historical standard is referenced on
Waters, Vol 2, 1997, pp. 34-73. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G52 − 00 (2011)
with fresh surface seawater. Additionally, some aspects may specimen contact areas with mounting devices may produce
also be applicable to deep ocean testing. crevice corrosion of some susceptible materials, for example,
some stainless steel and aluminum alloys.
NOTE 1—Guide G78 provides guidance for conducting crevice corro-
sion tests under controlled seawater test conditions.
NOTE 4—Bolts used to secure the insulators must be galvanically
compatible with the test rack.
4.2 While the duration of testing may be dictated by the test
objectives, exposures of more than six months or one year are 6.3 Spacing of the mounted specimens can be important. It
commonly used to minimize the effects of environmental is desirable to have sufficient space between surfaces of test
variables associated with seasonal changes or geographic specimens to ensure that adequate water flows between them
location, or both. and that with long exposures the accumulated fouling will not
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
configured to assess the effects of crevices, or both, such as 6.4 Specimen location maps or charts should be prepared
those described in Guide G78. In addition, they are useful for and maintained to ensure positive identification at the conclu-
testing of actual components and fabricated assemblies. sion of testing. Pre-exposure photographs of assembled test
racks are useful.
4.4 It is prudent to include control materials with known
resistance to seawater corrosion or fouling, or both, as de- 6.5 Racks may be suspended by such materials as nylon,
scribed in Test Method D3623. polyester, or polypropylene rope depending on prevailing
conditions. Steel wire rope should be avoided.
NOTE 2—Materials which have been included in ASTM Worldwide
6.5.1 For multiple year exposures, it is recommended that
Seawater Corrosivity Studies include UNS K01501 (carbon steel), UNS
2,4
the rack support rope be resistant to degradation by seawater as
C70600 (90/10 CuNi) and UNS A95086 (5086-H116 Al).
NOTE 3—In the case of evaluations of aluminum alloys, care should be
well as ultraviolet light.
exercised in the location of specimens near copper or high copper-
6.6 Exposure racks should be suspended so that attached
containing alloys. In some instances, it is not sufficient to simply
electrically isolate specimens to prevent bi-metallic (galvanic) corrosion; specimens will be oriented vertically and subjected to the full
copper ions from nearby corroding copper or copper-base alloys can
effects of the seawater but free of galvanic contact with other
deposit on aluminum and accelerate its corrosion.
specimens and with minimal sedimentation of silt and debris
on the specimen.
5. Test Sites
6.6.1 It should be recognized that in time some support
5.1 Test sites should be chosen at locations representative of
ropes may stretch due to the added mass of marine fouling. In
natural seawater environments where the metals or alloys to be
shallow waters, this should be taken into account to avoid
tested may be used. Ideally, a natural seawater test site should
unwanted contact with the sea bed or bottom. In some cases,
have clean, uncontaminated seawater, be in a protected loca-
the added mass will also make test rack removal more difficult.
tion, and have facilities for such tests as splash, tidal, and full
NOTE5—Itshouldberecognizedthatbarnaclesattachedtoracksupport
immersion. Reference should be made to tropical versus other
ropes will create potential hazards if manual lifting is required.
conditions, and seasonal variations in temperature and in
6.7 If periodic removals are envisioned, it is recommended
deposition of marine growth on the test panels with a defined
that different racks be utilized to support specimens for each
“fouling season.”
test period. Otherwise, marine fouling and corrosion products
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-
dures. 7.1 When the material to be tested is in sheet form, a
nominal specimen size of 100 by 300 mm (approximately 4 by
6. Exposure Racks
12 in.) is recommended. Specimens may be larger or smaller to
6.1 Test racks should be constructed of a material that will suit a particular test.
remain intact for the entire proposed period of exposure.
7.2 Odd shaped samples and assemblies comprising like or
Nickel-copper alloy 400 (UNS No. N04400) has been found to
dissimilar metals can also be tested. If testing materials in odd
be an excellent material, but is not recommended for holding
shapes (bolts, nuts, pipes, and so forth) is desired, a means of
aluminum specimens. Coated aluminum racks (6061-T6 or
supporting them in the test racks must be devised. It is
5086-H32) also have given satisfactory service. Nonmetallic
important that the specimens be electrically insulated from
racks made from reinforced plastic or treated wood might also
their respective supports and from each other to prevent
be used.
formation of galvanic corrosion cells. In some instances it is
6.2 Specimens must be insulated from the test racks. not sufficient to isolate specimens electricall
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.