1、Designation:G9507(Reapproved 2013)Standard Test Method forCathodic Disbondment Test of Pipeline Coatings(AttachedCell Method)1This standard is issued under the fixed designation G95;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the
2、 year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers accelerated procedures forsimultaneously determining comparative characteristics ofcoating s
3、ystems applied to steep pipe exterior for the purposeof preventing or mitigating corrosion that may occur inunderground service where the pipe will be in contact withnatural soils and will receive cathodic protection.They areintended for use with samples of coated pipe taken fromcommercial productio
4、n and are applicable to such sampleswhen the coating is characterized by function as an electricalbarrier.1.2 This test method is intended to facilitate testing ofcoatings where the test cell is cemented to the surface of thecoated pipe specimen.This is appropriate when it is impracti-cal to submerg
5、e or immerse the test specimen as required byTest Methods G8,G42,or G80.Coating sample configurationsuch as flat plate and small diameter pipe may be used,provided that the test procedure remains unchanged.21.3 This test method allows options that must be identifiedin the report.1.4 The values state
6、d in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and hea
7、lth practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3G8 Test Methods for Cathodic Disbonding of Pipeline Coat-ingsG12 Test Method for Nondestructive Measurement of FilmThickness of Pipeline Coatings on Steel(Withdrawn2013)4G4
8、2 Test Method for Cathodic Disbonding of PipelineCoatings Subjected to Elevated TemperaturesG62 Test Methods for Holiday Detection in Pipeline Coat-ingsG80 Test Method for Specific Cathodic Disbonding of Pipe-line Coatings(Withdrawn 2013)43.Summary of Test Method3.1 The test method described subject
9、s the coating on thetest specimen to electrical stress in a highly conductive alkalineelectrolyte.Electrical stress is obtained from an impresseddirect-current system.An intentional holiday is to be made inthe coating prior to starting of test.3.1.1 Electrical instrumentation is provided for measuri
10、ngthe current and the potential throughout the test cycle.At theconclusion of the test period,the test specimen is physicallyexamined.3.1.2 Physical examination is conducted by comparing theextent of loosened or disbonded coating at the intentionalholiday in the immersed area with extent of loosened
11、 ordisbonded coating at a reference holiday made in the coating inan area that was not immersed.4.Significance and Use4.1 Damage to pipe coating is almost unavoidable duringtransportation and construction.Breaks or holidays in pipe1This test method is under the jurisdiction of ASTM Committee D01 on
12、Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.48 on Durability of Pipeline Coating and Linings.Current edition approved June 1,2013.Published June 2013.Originallyapproved in 1987.Last previous edition approved in 2007 as G95 07.DOI:10.1520/G
13、0095-07R13.2For other cathodic disbondment testing procedures,consult Test Methods G8,G42,and G80.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document
14、Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 coatings may expose the pipe to possible corrosion since,aftera pipe has b
15、een installed underground,the surrounding earthwill be moisture-bearing and will constitute an effectiveelectrolyte.Applied cathodic protection potentials may causeloosening of the coating,beginning at holiday edges.Sponta-neous holidays may also be caused by such potentials.This testmethod provides
16、 accelerated conditions for cathodic disbond-ment to occur and provides a measure of resistance of coatingsto this type of action.4.2 The effects of the test are to be evaluated by physicalexaminations and monitoring the current drawn by the testspecimen.Usually there is no correlation between the twomethods of evaluation,but both methods are significant.Physical examination consists of assessing the effective contactof the coating with the metal surface in terms of observeddifferences in the re
