ASTM G116-99

Standard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosion

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 under the name CLIMAT Test (CLassify Industrial and Marine ATmospheres) to determine corrosivity of atmospheres (2-4).
1.4 This standard does not purport to address all of the safety problems, 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

• Status: Historical
• Publication Date: 09-Apr-1999
• ICS: 25.220.40 - Metallic coatings
• ICS: 77.060 - Corrosion of metals
• Technical Committee: G01 - Corrosion of Metals
• Drafting Committee: G01.04 - Corrosion of Metals in Natural Atmospheric and Aqueous Environments

Relations

• Replaced By: ASTM G116-99(2004) - Standard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosion
• Effective Date: 01-Nov-2004
• Referred By: ASTM G31-21 - Standard Guide for Laboratory Immersion Corrosion Testing of Metals
• Effective Date: 10-Apr-1999

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: G 116 – 99
Standard Practice for
Conducting Wire-on-Bolt Test for Atmospheric Galvanic
Corrosion
This standard is issued under the fixed designation G 116; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope Surfaces Exposed to Wetting Conditions as in Atmospheric
Corrosion Testing
1.1 This practice covers the evaluation of atmospheric
G 91 Practice for Monitoring Atmospheric SO Using the
galvanic corrosion of any anodic material that can be made into
Sulfation Plate Technique
a wire when in contact with a cathodic material that can be
G 92 Practice for Characterization of Atmospheric Test
made into a threaded rod.
Sites
1.2 When certain materials are used for the anode and
G 104 Test Method for Assessing Galvanic Corrosion
cathode, this practice has been used to rate the corrosivity of
Caused by the Atmosphere
atmospheres.
1.3 The wire-on-bolt test was first described in 1955 (1),
3. Terminology
and has since been used extensively with standard materials to
3.1 For definitions of terms used in this practice, refer to
determine corrosivity of atmospheres under the names CLI-
Terminology G 15. For conventions related to this method,
MAT Test (CLassify Industrial and Marine ATmospheres) (2-5)
refer to Practice G 3.
and ATCORR (ATmospheric CORRosivity) (6-9).
1.4 This standard does not purport to address all of the
4. Summary of Practice
safety concerns, if any, associated with its use. It is the
4.1 The practice consists of wrapping a wire of the anode
responsibility of the user of this standard to establish appro-
material around the threads of a bolt or threaded rod of the
priate safety and health practices and determine the applica-
cathode material, exposing the assembly to atmosphere, and
bility of regulatory limitations prior to use.
determining mass loss of the anode wire after exposure.
Reference specimens of the anode wire on a threaded, non-
2. Referenced Documents
conductive, non-porous rod are used to separate general and
2.1 ASTM Standards:
crevice corrosion effects from galvanic corrosion effects.
G 1 Practice for Preparing, Cleaning, and Evaluating Cor-
rosion Test Specimens
5. Significance and Use
G 3 Practice for Conventions Applicable to Electrochemical
3 5.1 The small size of the wire compared to the short
Measurements in Corrosion Testing
galvanic interaction distance in atmospheric exposures gives a
G 15 Terminology Relating to Corrosion and Corrosion
3 large cathode-to-anode area ratio which accelerates the gal-
Testing
vanic attack. The area between the wire and the threads creates
G 16 Guide for Applying Statistics to Analysis of Corrosion
3 a long, tight crevice, also accelerating the corrosion. For these
Data
reasons, this practice, with a typical exposure period of 90
G 50 Practice for Conducting Atmospheric Corrosion Tests
3 days, is the most rapid atmospheric galvanic corrosion test,
on Metals
particularly compared to Test Method G 104. The short dura-
G 82 Guide for Development and Use of a Galvanic Series
3 tion of this test means that seasonal atmospheric variability can
for Predicting Galvanic Corrosion Performance
be evaluated. (If average performance over a 1-year period is
G 84 Practice for Measurement of Time-of-Wetness on
desired, several staggered exposures are required with this
technique.) Reproducibility of this practice is somewhat better
than other atmospheric galvanic corrosion tests.
This practice is under the jurisdiction of ASTM Committee G-1 on Corrosion
of Metals and is the direct responsibility of Subcommittee G01.04 on Atmospheric 5.2 The major disadvantage of this test is that the anode
Corrosion.
material must be available in wire form and the cathodic
Current edition approved April 10, 1999. Published June 1999. Originally
published as G 116 – 93. Last previous edition G 116 – 93.
The boldface numbers in parentheses refer to the list of references at the end of
this standard.
3 4
Annual Book of ASTM Standards, Vol 03.02. Nylon 66 has been found suitable for this purpose.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
G116
material must be available in the form of a threaded rod. This
should be compared to Test Method G 104 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 G 82) 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 G 104 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.
6. Interferences
6.1 The manufacturing process used to make the wire and
rod may affect their corrosion potentials and polarization
behavior. Material in these forms may not behave galvanically
the same as material in the form of interest, such as fasteners
in sheet roofing for example. Although unlikely, this may even
FIG. 1 Components for Making Wire-on-Bolt Exposure
lead to a situation where reversing the materials may also Assemblies
reverse their anode-cathode relationship, resulting in attack
during service of a material which was resistant during testing
7.2.4 Wrap the wire tightly around the rod so that it lies
as a wire.
inside the threads using a jig such as that shown in Fig. 2. This
7. Procedure jig is used to keep constant tension on the wire while it is being
wound. While using this jig, wear clean cotton gloves to
7.1 Components:
prevent contamination of the surfaces of the wire or rod. If it is
7.1.1 The components used to construct the specimen as-
felt that the wire tension is not critical for the particular
semblies for this test are shown in Fig. 1.
application being tested, replace the use of the jig with
7.1.2 Prepare a 1-m length of 0.875 + 0.002-mm diameter
hand-winding.
wire of the anode material for each assembly. Other diameters
may be used, however, the diameter of the wire may affect the
test results, so that tests may only be compared if they use wire
of similar diameters. In selecting material for the wire, consider
the cold work and heat treatment of a wire may be significantly
different than for the component that the exposure is modeling.
7.1.3 Make the cathode material into M12 3 1.75 ( ⁄2 -13
-UNC threaded rods or bolts, 100-mm long. Either metric or
English threads may be used, but results may only be compared
between assemblies with similar thread types.
7.2 Making the Assemblies:
7.2.1 Thoroughly clean and degrease all parts before assem-
bly in accordance with Practice G 1.
7.2.2 Determine the mass of the wire to the nearest 0.0001
g.
7.2.3 Secure one end of the wire to a threaded rod using
small screws and nuts of the rod material, if possible, or of
nylon, stainless steel insulated with nylon, acetal resin, or
TFE-fluorocarbon. Plastic washers are usually used under the
heads of the screws. The wire may instead be secured to the rod
by means of a tight O-ring wrapped around the threaded rod
FIG. 2 Constant Tension Coil Winder for Wrapping Wire or
and the wire together. Threaded Rods
G116
7.2.5 Wind the wire until it is in contact with roughly an
axial distance of 50 mm of threaded rod.
7.2.6 Secure the free wire end to the rod by means of small
screws and nuts made of the rod material, if possible, or of
nylon, stainless steel insulated with nylon, acetal res
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