ASTM G42-96(2003)

Standard Test Method for Cathodic Disbonding of Pipeline Coatings Subjected to Elevated Temperatures

SCOPE
1.1 This test method describes an accelerated procedure for determining comparative characteristics of insulating coating systems applied to steel pipe exterior for the purpose of preventing or mitigating corrosion that may occur in underground service where the pipe will be exposed to high temperatures and is under cathodic protection. This test method is intended for use with samples of coated pipe taken from commercial production and is applicable to such samples when the coating is characterized by function as an electrical barrier.
1.2 This test method is intended for testing coatings submerged or immersed in the test solution at elevated temperature. When it is impractical to submerge or immerse the test specimen, Test Method G 95 may be considered where the test cell is cemented to the surface of the coated pipe specimen. If room temperatures are required, see Test Methods G 8. If a specific test method is required with no options, see Test Method G 80.
1.3 The values stated in SI units to three significant decimals are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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

• Status: Historical
• Publication Date: 30-Nov-2003
• ICS: 23.040.01 - Pipeline components and pipelines in general
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.48 - Durability of Pipeline Coating and Linings

Relations

• Replaces: ASTM G42-96 - Standard Test Method for Cathodic Disbonding of Pipeline Coatings Subjected to Elevated Temperatures
• Effective Date: 01-Dec-2003
• Replaced By: ASTM G42-11 - Standard Test Method for Cathodic Disbonding of Pipeline Coatings Subjected to Elevated Temperatures
• Effective Date: 15-Nov-2011
• Referred By: ASTM D6577-15(2019) - Standard Guide for Testing Industrial Protective Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM G95-07(2021) - Standard Test Method for Cathodic Disbondment Test of Pipeline Coatings (Attached Cell Method)
• Effective Date: 01-Dec-2003
• Referred By: ASTM A934/A934M-22 - Standard Specification for Epoxy-Coated Prefabricated Steel Reinforcing Bars
• Effective Date: 01-Dec-2003
• Referred By: ASTM D6676/D6676M-21 - Standard Test Method for Cathodic Disbonding of Exterior Pipeline Coatings at Elevated Temperatures Using Interior Heating
• Effective Date: 01-Dec-2003
• Referred By: ASTM G8-96(2019) - Standard Test Methods for Cathodic Disbonding of Pipeline Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM D7230-06(2021) - Standard Guide for Evaluating Polymeric Lining Systems for Water Immersion in Coating Service Level III Safety-Related Applications on Metal Substrates
• Effective Date: 01-Dec-2003

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:G42–96(Reapproved2003)
Standard Test Method for
Cathodic Disbonding of Pipeline Coatings Subjected to
1
Elevated Temperatures
ThisstandardisissuedunderthefixeddesignationG42;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G12 Test Method for Nondestructive Measurement of Film
Thickness of Pipeline Coatings on Steel
1.1 This test method describes an accelerated procedure for
G80 Test Method for Specific Cathodic Disbonding of
determining comparative characteristics of insulating coating
Pipeline Coatings
systems applied to steel pipe exterior for the purpose of
G95 Test Method for Cathodic Disbondment Test of Pipe-
preventing or mitigating corrosion that may occur in under-
line Coatings (Attached Cell Method)
ground service where the pipe will be exposed to high
temperaturesandisundercathodicprotection.Thistestmethod
3. Summary of Test Method
is intended for use with samples of coated pipe taken from
3.1 This test method subjects the coating on the test speci-
commercialproductionandisapplicabletosuchsampleswhen
men to electrical stress in a highly conductive electrolyte. The
the coating is characterized by function as an electrical barrier.
coating is artificially perforated before starting the test. The
1.2 This test method is intended for testing coatings sub-
electrical stress is produced by connecting the test specimen to
merged or immersed in the test solution at elevated tempera-
the negative terminal of a source of direct current and by
ture. When it is impractical to submerge or immerse the test
connecting an anode to the positive terminal. Electrical instru-
specimen, Test Method G95 may be considered where the test
mentation is provided for measuring the current flowing in the
cell is cemented to the surface of the coated pipe specimen. If
cell.Theelectricalpotentialisalsomeasuredandthespecimen
room temperatures are required, see Test Methods G8.Ifa
is physically examined at intervals during the test period and
specific test method is required with no options, see Test
upon conclusion of the test.
Method G80.
3.1.1 The cathodic stress is applied under conditions of a
1.3 The values stated in SI units to three significant deci-
constant-elevated temperature.
mals are to be regarded as the standard. The values given in
parentheses are for information only.
4. Significance and Use
1.4 This standard does not purport to address all of the
4.1 Damage to pipe coating is almost unavoidable during
safety concerns, if any, associated with its use. It is the
transportation and construction. Breaks or holidays in pipe
responsibility of the user of this standard to establish appro-
coatings may expose the pipe to possible corrosion since, after
priate safety and health practices and determine the applica-
a pipe has been installed underground, the surrounding earth
bility of regulatory limitations prior to use.
will be moisture-bearing and will constitute an effective
2. Referenced Documents electrolyte. Applied cathodic protection potentials may cause
2 loosening of the coating, beginning at holiday edges. Sponta-
2.1 ASTM Standards:
neousholidaysmayalsobecausedbysuchpotentials.Thistest
G8 Test Methods for Cathodic Disbonding of Pipeline
method provides accelerated conditions for cathodic disbond-
Coatings
ment to occur and provides a measure of resistance of coatings
to this type of action.
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
4.2 The effects of the test are to be evaluated by physical
and Related Coatings, Materials, andApplications and is the direct responsibility of
examinations and monitoring the current drawn by the test
Subcommittee D01.48 on Durability of Pipeline Coating and Linings.
specimen. Usually there is no correlation between the two
Current edition approved Dec. 1, 2003. Published December 2003. Originally
methods of evaluation, but both methods are significant.
approved in 1975. Last previous edition approved in 1996 as G42–96. DOI:
10.1520/G0042-96R03.
Physicalexaminationconsistsofassessingtheeffectivecontact
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
of the coating with the metal surface in terms of observed
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
differences in the relative adhesive bond. It is usually found
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. that the cathodically disbonded area propagates from an area
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