ASTM G116-99(2020)e1
(Practice)Standard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosion
Standard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosion
SIGNIFICANCE AND USE
5.1 The small size of the wire compared to the short galvanic interaction distance in atmospheric exposures gives a large cathode-to-anode area ratio which accelerates the galvanic attack. The area between the wire and the threads creates a long, tight crevice, also accelerating the corrosion. For these reasons, this practice, with a typical exposure period of 90 days, is the most rapid atmospheric galvanic corrosion test, particularly compared to Test Method G104. The short duration of this test means that seasonal atmospheric variability can be evaluated. (If average performance over a 1-year period is desired, several staggered exposures are required with this technique.) Reproducibility of this practice is somewhat better than other atmospheric galvanic corrosion tests.
5.2 The major disadvantage of this test is that the anode material must be available in wire form and the cathodic material must be available in the form of a threaded rod. This should be compared to Test Method G104 where plate or sheet material is used exclusively.
5.3 An additional limitation is that the more anodic material of the pair must be known beforehand (from information such as in Guide G82) or assemblies must be made with the material combinations reversed.
5.4 The morphology of the corrosion attack or its effect on mechanical properties of the base materials cannot be assessed by this practice. Test Method G104 is preferable for this purpose.
5.5 This test has been used under the names CLIMAT and ATCORR to determine atmospheric corrosivity by exposing identical specimens made from 1100 aluminum (UNS A91100) wire wrapped around threaded rods of nylon, 1010 mild steel (UNS G10100 or G10080), and CA110 copper (UNS C11000). Atmospheric corrosivity is a function of the material that is corroding, however. The relative corrosivity of atmospheres could be quite different if a different combination of materials is chosen.
SCOPE
1.1 This practice covers the evaluation of atmospheric galvanic corrosion of any anodic material that can be made into a wire when in contact with a cathodic material that can be made into a threaded rod.
1.2 When certain materials are used for the anode and cathode, this practice has been used to rate the corrosivity of atmospheres.
1.3 The wire-on-bolt test was first described in 1955 (1),2 and has since been used extensively with standard materials to determine corrosivity of atmospheres under the names CLIMAT Test (CLassify Industrial and Marine ATmospheres) (2-5) and ATCORR (ATmospheric CORRosivity) (6-9).
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: G116 − 99 (Reapproved 2020)
Standard Practice for
Conducting Wire-on-Bolt Test for Atmospheric Galvanic
Corrosion
This standard is issued under the fixed designation G116; 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.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Replaced Terminology G15 with Terminology G193, and other editorial changes made throughout in Dec. 2020.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers the evaluation of atmospheric
galvaniccorrosionofanyanodicmaterialthatcanbemadeinto G1Practice for Preparing, Cleaning, and Evaluating Corro-
sion Test Specimens
a wire when in contact with a cathodic material that can be
made into a threaded rod. G3Practice for Conventions Applicable to Electrochemical
Measurements in Corrosion Testing
1.2 When certain materials are used for the anode and
G16Guide for Applying Statistics to Analysis of Corrosion
cathode, this practice has been used to rate the corrosivity of
Data
atmospheres.
G50Practice for Conducting Atmospheric Corrosion Tests
1.3 The wire-on-bolt test was first described in 1955 (1),
on Metals
and has since been used extensively with standard materials to
G82Guide for Development and Use of a Galvanic Series
determine corrosivity of atmospheres under the names CLI-
for Predicting Galvanic Corrosion Performance
MAT Test (CLassify Industrial and Marine ATmospheres)
G84Practice for Measurement of Time-of-Wetness on Sur-
(2-5) and ATCORR (ATmospheric CORRosivity) (6-9).
faces Exposed to Wetting Conditions as in Atmospheric
Corrosion Testing
1.4 The values stated in SI units are to be regarded as
G91Practice for Monitoring Atmospheric SO Deposition
standard. No other units of measurement are included in this 2
Rate for Atmospheric Corrosivity Evaluation
standard.
G92Practice for Characterization ofAtmospheric Test Sites
1.5 This standard does not purport to address all of the
G104TestMethodforAssessingGalvanicCorrosionCaused
safety concerns, if any, associated with its use. It is the
by the Atmosphere (Withdrawn 1998)
responsibility of the user of this standard to establish appro-
G193Terminology and Acronyms Relating to Corrosion
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3. Terminology
1.6 This international standard was developed in accor-
3.1 For definitions of terms used in this practice, refer to
dance with internationally recognized principles on standard-
Terminology G193. For conventions related to this method,
ization established in the Decision on Principles for the
refer to Practice G3.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4. Summary of Practice
Barriers to Trade (TBT) Committee.
4.1 The practice consists of wrapping a wire of the anode
material around the threads of a bolt or threaded rod of the
cathode material, exposing the assembly to atmosphere, and
This practice is under the jurisdiction ofASTM Committee G01 on Corrosion
of Metals and is the direct responsibility of Subcommittee G01.04 on Corrosion of
Metals in Natural Atmospheric and Aqueous Environments. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2020. Published December 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approvedin1993.Lastpreviouseditionapprovedin2015asG116–99(2015).DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/G0116-99R20E01. the ASTM website.
2 4
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof The last approved version of this historical standard is referenced on
this standard. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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G116 − 99 (2020)
determining mass loss of the anode wire after exposure.
Reference specimens of the anode wire on a threaded, non-
conductive, non-porous rod are used to separate general and
crevice corrosion effects from galvanic corrosion effects.
5. Significance and Use
5.1 The small size of the wire compared to the short
galvanic interaction distance in atmospheric exposures gives a
large cathode-to-anode area ratio which accelerates the gal-
vanicattack.Theareabetweenthewireandthethreadscreates
a long, tight crevice, also accelerating the corrosion. For these
reasons, this practice, with a typical exposure period of 90
days, is the most rapid atmospheric galvanic corrosion test,
particularlycomparedtoTestMethodG104.Theshortduration
of this test means that seasonal atmospheric variability can be
evaluated. (If average performance over a 1-year period is
desired, several staggered exposures are required with this
technique.) Reproducibility of this practice is somewhat better
than other atmospheric galvanic corrosion tests.
5.2 The major disadvantage of this test is that the anode
material must be available in wire form and the cathodic
material must be available in the form of a threaded rod. This
should be compared toTest Method G104 where plate or sheet
material is used exclusively.
5.3 Anadditionallimitationisthatthemoreanodicmaterial
of the pair must be known beforehand (from information such
FIG. 1 Components for Making Wire-on-Bolt Exposure Assem-
asinGuideG82)orassembliesmustbemadewiththematerial
blies
combinations reversed.
5.4 The morphology of the corrosion attack or its effect on
7.1.2 Prepare a 1m length of 0.875mm + 0.002mm diam-
mechanical properties of the base materials cannot be assessed
eter wire of the anode material for each assembly. Other
by this practice. Test Method G104 is preferable for this
diameters may be used, however, the diameter of the wire may
purpose.
affect the test results, so that tests may only be compared if
5.5 This test has been used under the names CLIMAT and theyusewireofsimilardiameters.Inselectingmaterialforthe
wire, consider the cold work and heat treatment of a wire may
ATCORR to determine atmospheric corrosivity by exposing
identicalspecimensmadefrom1100aluminum(UNSA91100) be significantly different than for the component that the
exposure is modeling.
wire wrapped around threaded rods of nylon, 1010 mild steel
(UNSG10100orG10080),andCA110copper(UNSC11000). 7.1.3 Make the cathode material into M12 × 1.75 ( ⁄2-13-
UNC threaded rods or bolts, 100mm long. Either metric or
Atmospheric corrosivity is a function of the material that is
corroding, however. The relative corrosivity of atmospheres Englishthreadsmaybeused,butresultsmayonlybecompared
between assemblies with similar thread types.
could be quite different if a different combination of materials
is chosen.
7.2 Making the Assemblies:
7.2.1 Thoroughlycleananddegreaseallpartsbeforeassem-
6. Interferences
bly in accordance with Practice G1.
6.1 The manufacturing process used to make the wire and
7.2.2 Determine the mass of the wire to the nearest
rod may affect their corrosion potentials and polarization
0.0001g.
behavior. Material in these forms may not behave galvanically
7.2.3 Secure one end of the wire to a threaded rod using
the same as material in the form of interest, such as fasteners
small screws and nuts of the rod material, if possible, or of
in sheet roofing for example.Although unlikely, this may even
nylon, stainless steel insulated with nylon, acetal resin, or
lead to a situation where reversing the materials may also
TFE-fluorocarbon. Plastic washers are usually used under the
reverse their anode-cathode relationship, resulting in attack
headsofthescrews.Thewiremayinsteadbesecuredtotherod
during service of a material which was resistant during testing
by means of a tight O-ring wrapped around the threaded rod
as a wire.
and the wire together.
7.2.4 Wrap the wire tightly around the rod so that it lies
7. Procedure
inside the threads using a jig such as that shown in Fig. 2.This
7.1 Components: jigisusedtokeepconstanttensiononthewirewhileitisbeing
7.1.1 The components used to construct the specimen as- wound. While using this jig, wear clean cotton gloves to
semblies for this test are shown in Fig. 1. preventcontaminationofthesurfacesofthewireorrod.Ifitis
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G116 − 99 (2020)
schematic of a completed assembly, and Fig. 4 is a photograph
of an actual completed assembly just before exposure.
7.3.2 Mount the plates horizontally on racks such as de-
scribed in Practice G50.
7.3.3 Expose the asse
...
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