ASTM G116-99(2010)
(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
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 . 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.
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 where plate or sheet material is used exclusively.
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.
The morphology of the corrosion attack or its effect on mechanical properties of the base materials cannot be assessed by this practice. Test Method is preferable for this purpose.
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), 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 and health practices and determine the applicability of regulatory limitations prior to use.
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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: G116 − 99(Reapproved 2010)
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.
1. Scope ing (Withdrawn 2010)
G16Guide for Applying Statistics to Analysis of Corrosion
1.1 This practice covers the evaluation of atmospheric
Data
galvaniccorrosionofanyanodicmaterialthatcanbemadeinto
G50Practice for Conducting Atmospheric Corrosion Tests
a wire when in contact with a cathodic material that can be
on Metals
made into a threaded rod.
G82Guide for Development and Use of a Galvanic Series
1.2 When certain materials are used for the anode and
for Predicting Galvanic Corrosion Performance
cathode, this practice has been used to rate the corrosivity of
G84Practice for Measurement of Time-of-Wetness on Sur-
atmospheres.
faces Exposed to Wetting Conditions as in Atmospheric
Corrosion Testing
1.3 The wire-on-bolt test was first described in 1955 (1),
and has since been used extensively with standard materials to G91Practice for Monitoring Atmospheric SO Deposition
Rate for Atmospheric Corrosivity Evaluation
determine corrosivity of atmospheres under the names CLI-
MAT Test (CLassify Industrial and Marine ATmospheres) G92Practice for Characterization ofAtmospheric Test Sites
G104TestMethodforAssessingGalvanicCorrosionCaused
(2-5) and ATCORR (ATmospheric CORRosivity) (6-9).
by the Atmosphere (Withdrawn 1998)
1.4 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3. Terminology
standard.
3.1 For definitions of terms used in this practice, refer to
1.5 This standard does not purport to address all of the
TerminologyG15.Forconventionsrelatedtothismethod,refer
safety concerns, if any, associated with its use. It is the
to Practice G3.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Summary of Practice
bility of regulatory limitations prior to use.
4.1 The practice consists of wrapping a wire of the anode
material around the threads of a bolt or threaded rod of the
2. Referenced Documents
cathode material, exposing the assembly to atmosphere, and
2.1 ASTM Standards:
determining mass loss of the anode wire after exposure.
G1Practice for Preparing, Cleaning, and Evaluating Corro-
Reference specimens of the anode wire on a threaded, non-
sion Test Specimens
conductive, non-porous rod are used to separate general and
G3Practice for Conventions Applicable to Electrochemical
crevice corrosion effects from galvanic corrosion effects.
Measurements in Corrosion Testing
G15Terminology Relating to Corrosion and CorrosionTest-
5. Significance and Use
5.1 The small size of the wire compared to the short
galvanic interaction distance in atmospheric exposures gives a
This practice is under the jurisdiction ofASTM Committee G01 on Corrosion
large cathode-to-anode area ratio which accelerates the gal-
of Metals and is the direct responsibility of Subcommittee G01.04 on Atmospheric
vanicattack.Theareabetweenthewireandthethreadscreates
Corrosion.
a long, tight crevice, also accelerating the corrosion. For these
Current edition approved May 1, 2010. Published May 2010. Originally
approvedin1993.Lastpreviouseditionapprovedin2004asG116–99(2004).DOI: reasons, this practice, with a typical exposure period of 90
10.1520/G0116-99R10.
days, is the most rapid atmospheric galvanic corrosion test,
The boldface numbers in parentheses refer to the list of references at the end of
particularlycomparedtoTestMethodG104.Theshortduration
this standard.
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G116 − 99 (2010)
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
asinGuideG82)orassembliesmustbemadewiththematerial
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
identicalspecimensmadefrom1100aluminum(UNSA91100)
wire wrapped around threaded rods of nylon, 1010 mild steel
(UNSG10100orG10080),andCA110copper(UNSC11000).
Atmospheric corrosivity is a function of the material that is
corroding, however. The relative corrosivity of atmospheres
FIG. 1 Components for Making Wire-on-Bolt Exposure Assem-
could be quite different if a different combination of materials
blies
is chosen.
6. Interferences
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
7.1.2 Prepare a 1-m length of 0.875 + 0.002-mm diameter
felt that the wire tension is not critical for the particular
wire of the anode material for each assembly. Other diameters
application being tested, replace the use of the jig with
may be used, however, the diameter of the wire may affect the
hand-winding.
testresults,sothattestsmayonlybecomparediftheyusewire
7.2.5 Wind the wire until it is in contact with roughly an
ofsimilardiameters.Inselectingmaterialforthewire,consider
axial distance of 50 mm of threaded rod.
thecoldworkandheattreatmentofawiremaybesignificantly
7.2.6 Secure the free wire end to the rod by means of small
differentthanforthecomponentthattheexposureismodeling.
screws and nuts made of the rod material, if possible, or of
7.1.3 Make the cathode material into M12 × 1.75 ( ⁄2-13-
nylon, stainless steel insulated with nylon, acetal resin, or
UNC threaded rods or bolts, 100-mm long. Either metric or
TFE-fluorocarbon. Plastic washers are usually used under the
Englishthreadsmaybeused,butresultsmayonlybecompared
headsofscrews.Thewiremayinsteadbesecuredtotherodby
between assemblies with similar thread types.
means of a tight O-ring wrapped around the threaded rod and
7.2 Making the Assemblies: the wire together.
7.2.1 Thoroughlycleananddegreaseallpartsbeforeassem- 7.2.7 Clip off the excess wire, if any, and determine the
bly in accordan
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