ASTM G161-00(2018)

Standard Guide for Corrosion-Related Failure Analysis

SIGNIFICANCE AND USE
3.1 This guide is intended to assist those encountering corrosion or possible corrosion as a causative factor in a failure analysis.  
3.2 This guide is not an absolute plan that will identify the cause of corrosion in all failure analyses.  
3.3 This guide is intended to help an investigator identify significant sources and types of corrosion information that may be available for failure analysis.  
3.4 Appendix X1 contains a checklist that is intended to assist in corrosion-related failure evaluations.
SCOPE
1.1 This guide covers key issues to be considered when examining metallic failures when corrosion is suspected as either a major or minor causative factor.  
1.2 Corrosion-related failures could include one or more of the following: change in surface appearance (for example, tarnish, rust, color change), pin hole leak, catastrophic structural failure (for example, collapse, explosive rupture, implosive rupture, cracking), weld failure, loss of electrical continuity, and loss of functionality (for example, seizure, galling, spalling, swelling).  
1.3 Issues covered include overall failure site conditions, operating conditions at the time of failure, history of equipment and its operation, corrosion product sampling, environmental sampling, metallurgical and electrochemical factors, morphology (mode) or failure, and by considering the preceding, deducing the cause(s) of corrosion failure.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2018
• ICS: 77.060 - Corrosion of metals
• Technical Committee: G01 - Corrosion of Metals
• Drafting Committee: G01.05 - Laboratory Corrosion Tests

Relations

• Replaces: ASTM G161-00(2013) - Standard Guide for Corrosion-Related Failure Analysis
• Effective Date: 01-Oct-2018
• Refers: ASTM G46-94(2013) - Standard Guide for Examination and Evaluation of Pitting Corrosion
• Effective Date: 01-May-2013
• Refers: ASTM E1459-13 - Standard Guide for Physical Evidence Labeling and Related Documentation
• Effective Date: 15-Feb-2013
• Refers: ASTM G1-03(2011) - Standard Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
• Effective Date: 01-Dec-2011
• Refers: ASTM E1492-11 - Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
• Effective Date: 01-Jun-2011
• Refers: ASTM E3-01(2007) - Standard Guide for Preparation of Metallographic Specimens
• Effective Date: 01-Jul-2007
• Refers: ASTM E3-01(2007)e1 - Standard Guide for Preparation of Metallographic Specimens
• Effective Date: 01-Jul-2007
• Refers: ASTM E1492-05 - Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
• Effective Date: 15-Jul-2005
• Refers: ASTM G46-94(2005) - Standard Guide for Examination and Evaluation of Pitting Corrosion
• Effective Date: 01-May-2005
• Refers: ASTM E1459-92(2005) - Standard Guide for Physical Evidence Labeling and Related Documentation
• Effective Date: 01-May-2005
• Refers: ASTM G1-03 - Standard Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
• Effective Date: 01-Oct-2003
• Refers: ASTM E3-01 - Standard Practice for Preparation of Metallographic Specimens
• Effective Date: 10-Apr-2001
• Refers: ASTM E3-95 - Standard Practice for Preparation of Metallographic Specimens
• Effective Date: 10-Apr-2001
• Refers: ASTM E1492-92(1999) - Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
• Effective Date: 10-May-1999
• Refers: ASTM G46-94(1999) - Standard Guide for Examination and Evaluation of Pitting Corrosion
• Effective Date: 10-Jan-1999

Overview

ASTM G161-00(2018), Standard Guide for Corrosion-Related Failure Analysis, provides practical guidelines for investigating failures in metallic components where corrosion is suspected as a contributing factor. Developed by ASTM International, this standard is designed for use by engineers, failure analysts, forensic investigators, and maintenance professionals to systematically assess the role that corrosion may have played in a material or equipment failure. The standard outlines considerations for organizing and conducting corrosion-related failure analyses, emphasizing the importance of protecting evidence, documentation, and comprehensive evaluation.

Key Topics

• Identification of Corrosion-Related Causes: The guide helps users recognize signs of corrosion such as tarnish, rust, pitting, pinhole leaks, catastrophic failures (e.g., rupture, cracking), weld failures, and loss of functionality (e.g., seizing or swelling).
• Investigation Planning: Recommendations for early recognition and timely analysis, including preserving the failure site and developing a written analysis plan.
• Site and Equipment Evaluation: Guidance on examining failure site conditions, taking photographs, conducting interviews, and collecting relevant historical data about the equipment and its operating environment.
• Operating Conditions and History: Instructions for reviewing operating parameters before and during failure, documenting maintenance records, and noting design or operational changes.
• Sampling and Documentation: Emphasizes precise sampling techniques to avoid contamination, importance of labeled and documented samples, and comprehensive recording of details as per forensic best practices.
• Sample Evaluation: Covers determination of material composition, metallurgical condition, corrosion product analysis, and destructive and non-destructive testing procedures.
• Assessment and Reporting: Advice on consolidating findings, identifying causative factors, noting the extent of corrosion, and suggesting corrective actions.

Applications

Corrosion-related failure analysis guided by ASTM G161 is valuable in a wide range of sectors, including:

• Industrial Equipment: Analysis of piping, tanks, reactors, and machinery in the chemical, oil & gas, power generation, and water treatment industries.
• Infrastructure: Investigations into structural components, bridges, and transportation systems where metallic failures can have critical consequences.
• Manufacturing and Maintenance: Supporting quality assurance and preventive maintenance programs by identifying underlying corrosion mechanisms responsible for product or component breakdowns.
• Forensic Engineering: Assisting in accident investigations and root cause analyses where corrosion is a suspected factor in catastrophic failures or loss of function.
• Regulatory Compliance: Ensuring that corrosion failures and their contributing factors are thoroughly documented for insurance, legal, and regulatory reporting.

Related Standards

For comprehensive failure analysis and optimized sampling, ASTM G161 should be used alongside other relevant standards, such as:

• ASTM G1: Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
• ASTM G46: Guide for Examination and Evaluation of Pitting Corrosion
• ASTM E3: Guide for Preparation of Metallographic Specimens
• ASTM E1459: Guide for Physical Evidence Labeling and Related Documentation
• ASTM E1492: Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory

These documents offer additional procedures and detailed technical methods essential for thorough and accurate corrosion-related failure investigations.

By following ASTM G161, professionals can systematically identify corrosion's role in failures, implement corrective measures, and improve the reliability and safety of metallic systems. For greater operational value, integrate this standard as part of a holistic asset management and incident investigation program.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: G161 − 00 (Reapproved 2018)
Standard Guide for
Corrosion-Related Failure Analysis
This standard is issued under the fixed designation G161; 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.
1. Scope E1492 Practice for Receiving, Documenting, Storing, and
Retrieving Evidence in a Forensic Science Laboratory
1.1 This guide covers key issues to be considered when
G1 Practice for Preparing, Cleaning, and Evaluating Corro-
examining metallic failures when corrosion is suspected as
sion Test Specimens
either a major or minor causative factor.
G46 Guide for Examination and Evaluation of Pitting Cor-
1.2 Corrosion-related failures could include one or more of
rosion
the following: change in surface appearance (for example,
tarnish, rust, color change), pin hole leak, catastrophic struc-
3. Significance and Use
tural failure (for example, collapse, explosive rupture, implo-
3.1 This guide is intended to assist those encountering
sive rupture, cracking), weld failure, loss of electrical
corrosion or possible corrosion as a causative factor in a failure
continuity, and loss of functionality (for example, seizure,
analysis.
galling, spalling, swelling).
3.2 This guide is not an absolute plan that will identify the
1.3 Issues covered include overall failure site conditions,
cause of corrosion in all failure analyses.
operatingconditionsatthetimeoffailure,historyofequipment
3.3 This guide is intended to help an investigator identify
and its operation, corrosion product sampling, environmental
significant sources and types of corrosion information that may
sampling, metallurgical and electrochemical factors, morphol-
be available for failure analysis.
ogy (mode) or failure, and by considering the preceding,
deducing the cause(s) of corrosion failure.
3.4 Appendix X1 contains a checklist that is intended to
assist in corrosion-related failure evaluations.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Organizing the Analysis
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4.1 Early recognition of corrosion as a factor in a failure
mine the applicability of regulatory limitations prior to use.
analysis is critical to any such investigation. Therefore, it is
1.5 This international standard was developed in accor-
generally desirable to conduct the analysis as soon as possible
dance with internationally recognized principles on standard-
after the apparent failure. It is always desirable to protect the
ization established in the Decision on Principles for the
physical evidence until the analysis can begin. Much important
Development of International Standards, Guides and Recom-
corrosion information can be lost if a failure scene is altered or
mendations issued by the World Trade Organization Technical
changed before appropriate observations can be made.
Barriers to Trade (TBT) Committee.
4.2 A written plan for the detailed analysis should be
prepared. The plan may include methods of documentation
2. Referenced Documents
(photographsbeforeandduringanalysis,sketches,statements),
2.1 ASTM Standards:
responsibilities of parties, reporting needs, and scheduling.
E3 Guide for Preparation of Metallographic Specimens
4.3 If the capability (corrosion knowledge and experience)
E1459 Guide for Physical Evidence Labeling and Related
of in-house personnel and availability of resources are inad-
Documentation
equate to make the analysis in a timely manner, it may be
expedient to seek third party services.
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of
Metals and is the direct responsibility of Subcommittee G01.05 on Laboratory
Corrosion Tests.
5. Failure Site Conditions
Current edition approved Oct. 1, 2018. Published November 2018. Originally
5.1 When possible, an overall examination of the conditions
approved in 1999. Last previous edition approved in 2013 as G161 – 00 (2013).
DOI: 10.1520/G0161-00R18.
at a failure site prior to cleaning, moving, or sampling debris
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
should be conducted. Impressions as to physical arrangements,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
odors, colors, textures, and conditions of adjacent structures
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. can provide important clues as to active corrosion processes.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G161 − 00 (2018)
5.2 Photographs or videotapes serve as documentation of foroneormorereasons,including,butnotlimitedto,problems
theobservations.Colorphotographsarepreferable.Itishelpful with original design, changed service requirements, corrected
to include labels and indications of size, location, and orienta- earlier failures, and correction of safety and environmental
tion in the photographs. Photographs before, during, and after concerns. The same types of details suggested in 7.2 should be
sampling are recommended. considered regarding modifications.
5.3 Sketches and drawings with notes as to detailed obser- 7.4 Details regarding operating history may be important.
vations can be beneficial for later evaluations. Locations of Three types of operating information that may require docu-
samples and photographs may be shown. mentation are original design parameters, chronology of nomi-
naloperatingparameters,andanomalousoperatingparameters,
5.4 Interviews with those who were present or nearby when
including out-of-specification periods and significant down-
thefailureoccurredwouldbeappropriate.Informationontime,
time periods.
sights, sounds, and conditions can be gained during such
interviews. 7.5 Maintenance, cleaning, and repair histories may be
important and should be documented.
6. Operating Conditions At Time of Failure
7.6 Changesinspecificationfor,andsourcesof,processraw
6.1 Ascertain the operating conditions from operator’s logs,
materials and supplies may be significant and should be
recorders, and data loggers (verify the accuracy of time
evaluated.
records). Special attention should be given to the stability of
the operating conditions, for example, were they stable or 8. Sampling
variable. Conditions of corrosion concern could be
8.1 Careful sampling is critical to the successful investiga-
temperature, pressure, flow rate, velocity, process stream pH
tion of corrosion-related failures. Sampling in corrosion inves-
and chemical composition, time, and weather.
tigations is similar to that used in forensic investigations by
6.2 Special attention should be given to out-of-specification criminologists. Guide E1459 and Practice E1492 address
or other abnormal or unusual upset conditions. issues of labeling and documenting field evidence. These
standards may provide useful guidance during sampling for
6.3 It may be necessary to plot or track operating conditions
corrosion investigations.
for an indefinite period of time prior to the detection of failure
to more clearly identify any unusual, contributory operating 8.2 The written plan suggested in 4.2 should be supple-
conditions. mented with a written sampling plan. The plan should specify
a sample location, identification system, and method of collec-
6.4 If similar, parallel equipment at the same or other
tion.
location was operating at the time of the corrosion-related
failure, note the operating conditions as a reference point. Such
8.3 Avoid contamination during sampling by using clean
information could be useful in judging the normalcy of the tools. Personnel should wear gloves to avoid fingerprints and
operating conditions associated with the failure.
personal contact.
6.5 Corrosion monitoring instruments and coupons, if 8.4 Sample containers should be clean and sealable to
present, should be examined to help document operating
protect samples from contamination and damage. The material
conditions at the time of failure. of sample containers should be selected carefully to avoid
undesirable interaction with samples. Each container should be
7. Historical Information
dated and identified according to the sampling plan.
7.1 Historical information, when available, is extremely
8.5 Samples of corroded and uncorroded materials may be
useful in understanding some situations. All of the types of
useful in the identification of causative factors. Samples should
information noted may not be useful. Often in cases of older
be as large as practical to give analysts sufficient material to
equipment, historical information may be nearly impossible to
work with and to protect critical corroded areas from damage
find because of lost files or retired personnel. Based on cost,
during cutting and transporting. If failure initiation location is
time, and anticipated benefit, a judgement must be made as to
apparent, it should be sampled. When cutting samples, consid-
the effort one should expend in retrieving historical informa-
eration should be given to temperature control and to the
tion.
introduction of cutting and cooling fluids that could alter the
7.2 Useful details regarding original constructions may surface and metallurgical conditions. Because of the solubility
include, but are not limited to, design drawings and in water of many corrosion products, samples must be pro-
specifications, material specifications (composition, thermal tected from extraneous moisture.
treatments, surface treatments), joining (bolts, rivets, welds,
8.6 Corrosion products and deposits should be given special
adhesives), and surface treatments (coatings, pickling, etching,
sampling treatment because they are often key elements in
anodizing, plating, peening, grinding, insulation, or refracto-
understanding the failure. Care should be used in the selection
ries).
of tools for collecting these samples. Nonmetallic tools are
7.3 Details regarding modifications made subsequent to often preferred because they present less chance for contami-
original fabrication and prior to the corrosion-related failure nationofthesampleorfordamagingcriticalcorrodedsurfaces.
may be extremely important because they often reveal less- When there is insufficient corrosion product or deposit for easy
than-optimum field work. Modifications may have been made field sampling, care should be used when handling material so
-------------------
...