ASTM G78-15

Standard Guide for Crevice Corrosion Testing of Iron-Base and Nickel-Base Stainless Alloys in Seawater and Other Chloride-Containing Aqueous Environments

SIGNIFICANCE AND USE
4.1 This guide covers procedures for crevice-corrosion testing of iron-base and nickel-base stainless alloys in seawater. The guidance provided may also be applicable to crevice corrosion testing in other chloride containing natural waters and various laboratory prepared aqueous chloride environments.  
4.2 This guide describes the use of a variety of crevice formers including the nonmetallic, segmented washer design referred to as the multiple crevice assembly (MCA) as described in 9.2.2.  
4.3 In-service performance data provide the most reliable determination of whether a material would be satisfactory for a particular end use. Translation of laboratory data from a single test program to predict service performance under a variety of conditions should be avoided. Terms, such as immunity, superior resistance, etc., provide only a general and relatively qualitative description of an alloy's corrosion performance. The limitations of such terms in describing resistance to crevice corrosion should be recognized.  
4.4 While the guidance provided is generally for the purpose of evaluating sheet and plate materials, it is also applicable for crevice-corrosion testing of other product forms, such as tubing and bars.  
4.5 The presence or absence of crevice corrosion under one set of conditions is no guarantee that it will or will not occur under other conditions. Because of the many interrelated metallurgical, environmental, and geometric factors known to affect crevice corrosion, results from any given test may or may not be indicative of actual performance in service applications where the conditions may be different from those of the test.
SCOPE
1.1 This guide covers information for conducting crevice-corrosion tests and identifies factors that may affect results and influence conclusions.  
1.2 These procedures can be used to identify conditions most likely to result in crevice corrosion and provide a basis for assessing the relative resistance of various alloys to crevice corrosion under certain specified conditions.  
1.3 The values stated in SI units are to be regarded as 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. For a specific warning statement, see 7.1.

General Information

• Status: Historical
• Publication Date: 31-May-2015
• 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

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: G78 − 15
Standard Guide for
Crevice Corrosion Testing of Iron-Base and Nickel-Base
Stainless Alloys in Seawater and Other Chloride-Containing
1
Aqueous Environments
ThisstandardisissuedunderthefixeddesignationG78;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Crevice corrosion of iron-base and nickel-base stainless alloys can occur when an occlusion or
crevice limits access of the bulk environment to a localized area of the metal surface. Localized
environmental changes in this stagnant area can result in the formation of acidic/high chloride
conditions that may result in initiation and propagation of crevice corrosion of susceptible alloys.
In practice, crevices can generally be classified into two categories: (1) naturally occurring, that is,
those created by biofouling, sediment, debris, deposits, etc. and (2) man-made, that is, those created
during manufacturing, fabrication, assembly, or service. Crevice formers utilized in laboratory and
field studies can represent actual geometric conditions encountered in some service applications. Use
of such crevice formers in service-type environments are not considered accelerated test methods.
The geometry of a crevice can be described by the dimensions of crevice gap and crevice depth.
Crevice gap is identified as the width or space between the metal surface and the crevice former.
Crevice depth is the distance from the mouth to the center or base of the crevice.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This guide covers information for conducting crevice-
mendations issued by the World Trade Organization Technical
corrosion tests and identifies factors that may affect results and
Barriers to Trade (TBT) Committee.
influence conclusions.
1.2 These procedures can be used to identify conditions
2. Referenced Documents
mostlikelytoresultincrevicecorrosionandprovideabasisfor
2
2.1 ASTM Standards:
assessing the relative resistance of various alloys to crevice
G1Practice for Preparing, Cleaning, and Evaluating Corro-
corrosion under certain specified conditions.
sion Test Specimens
1.3 The values stated in SI units are to be regarded as
G4Guide for Conducting Corrosion Tests in Field Applica-
standard. The values given in parentheses are for information
tions
only.
G46Guide for Examination and Evaluation of Pitting Cor-
rosion
1.4 This standard does not purport to address all of the
G48Test Methods for Pitting and Crevice Corrosion Resis-
safety concerns, if any, associated with its use. It is the
tance of Stainless Steels and Related Alloys by Use of
responsibility of the user of this standard to establish appro-
Ferric Chloride Solution
priate safety and health practices and determine the applica-
G193Terminology and Acronyms Relating to Corrosion
bility of regulatory limitations prior to use. For a specific
warning statement, see 7.1.
3. Terminology
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3.1 Definitions of related terms can be found in Terminol-
ogy G193.
1
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of
Metals and is the direct responsibility of Subcommittee G01.04 on Corrosion of
2
Metals in Natural Atmospheric and Aqueous Environments. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJune1,2015.PublishedJuly2015.Originallyapproved contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
in 1983. Last previous edition approved in 2012 as G78–01 (2012). DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/G0078-15. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
G78−15
4. Significance and Use ;0.5 m/s (1.64 ft/s) or less) or quiescent conditions. Contain-
ers should be resistant to the test media.
4.1 This guide covers procedures for crevice-corrosion test-
ing of iron-base and nickel-base stainless alloys in seawater. 5.2 Fig. 1 shows a typical test apparatus for conducting
The guidance provided may also be applicable to crevice crevice-corrosiontestsundercontrolledtemperatureconditions
corrosion testing in other chloride containing natural waters with provisions for recirculation or refreshment of the aqueous
and various laboratory prepared aqueous chloride environ- environment, or both, at a constant level.
ments.
5.3 The apparatus
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: G78 − 01 (Reapproved 2012) G78 − 15
Standard Guide for
Crevice Corrosion Testing of Iron-Base and Nickel-Base
Stainless Alloys in Seawater and Other Chloride-Containing
1
Aqueous Environments
This standard is issued under the fixed designation G78; 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 (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Crevice corrosion of iron-base and nickel-base stainless alloys can occur when an occlusion or
crevice limits access of the bulk environment to a localized area of the metal surface. Localized
environmental changes in this stagnant area can result in the formation of acidic/high chloride
conditions that may result in initiation and propagation of crevice corrosion of susceptible alloys.
In practice, crevices can generally be classified into two categories: (1) naturally occurring, that is,
those created by biofouling, sediment, debris, deposits, etc. and (2) man-made, that is, those created
during manufacturing, fabrication, assembly, or service. Crevice formers utilized in laboratory and
field studies can represent actual geometric conditions encountered in some service applications. Use
of such crevice formers in service-type environments are not considered accelerated test methods.
The geometry of a crevice can be described by the dimensions of crevice gap and crevice depth.
Crevice gap is identified as the width or space between the metal surface and the crevice former.
Crevice depth is the distance from the mouth to the center or base of the crevice.
1. Scope
1.1 This guide covers information for conducting crevice-corrosion tests and identifies factors that may affect results and
influence conclusions.
1.2 These procedures can be used to identify conditions most likely to result in crevice corrosion and provide a basis for
assessing the relative resistance of various alloys to crevice corrosion under certain specified conditions.
1.3 The values stated in SI units are to be regarded as 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. For a specific warning statement, see 7.1.17.1.
2. Referenced Documents
2
2.1 ASTM Standards:
G1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
G4 Guide for Conducting Corrosion Tests in Field Applications
3
G15 Terminology Relating to Corrosion and Corrosion Testing (Withdrawn 2010)
G46 Guide for Examination and Evaluation of Pitting Corrosion
G48 Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride
Solution
G193 Terminology and Acronyms Relating to Corrosion
1
This guide is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subcommittee G01.09 on Corrosion in Natural
Waters.
Current edition approved Nov. 1, 2012June 1, 2015. Published November 2012July 2015. Originally approved in 1983. Last previous edition approved in 20072012 as
G78–01 (2007).(2012). DOI: 10.1520/G0078-01R12.10.1520/G0078-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
G78 − 15
3. Terminology
3.1 Definitions of related terms can be found in Terminology G15G193.
4. Significance and Use
4.1 This guide covers procedures for crevice-corrosion testing of iron-base and nickel-base stainless alloys in seawater. The
guidance provided may also be applicable to crevicecorrosion crevice corrosion testing in other chloride containing natural waters
and various laboratory prepared aqueous chloride environments.
4.2 This guide describes the use of a variety of crevice formers including the nonmetallic, segmented washer design referred
to as the multiple crevice assembly (MCA) as described in 9.2.2.
4.3 In-se
...