ASTM G50-10(2015)

Standard Practice for Conducting Atmospheric Corrosion Tests on Metals

SIGNIFICANCE AND USE
3.1 The procedures described herein can be used to evaluate the corrosion resistance of metals when exposed to the weather, as well as to evaluate the relative corrosivity of the atmosphere at specific locations. Because of the variability and complexity of weather effects and the industrial and natural factors influencing the atmospheric corrosivity of a test site, a multi-year exposure period should be considered to minimize their influence. Also, as corrosivity may vary at a site from season to season, exposures should be made either at the same time of the year to minimize variability or these differences should be established by multiple exposures.  
3.2 Control specimens should always be employed in weathering tests. The control specimens should be from a material having established weathering characteristics. A substantial amount of corrosion data shall have been accumulated for the control specimens. It is also good practice to retain samples of all materials exposed so that possible effects of long-term aging can be measured.
SCOPE
1.1 This practice covers and defines conditions for exposure of metals and alloys to the weather. It sets forth the general procedures that should be followed in any atmospheric test. It is presented as an aid in conducting atmospheric corrosion tests so that some of the pitfalls of such testing may be avoided. As such, it is concerned mainly with panel exposures to obtain data for comparison purposes.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Oct-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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: G50 − 10 (Reapproved 2015)
Standard Practice for
1
Conducting Atmospheric Corrosion Tests on Metals
This standard is issued under the fixed designation G50; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G91 Practice for Monitoring Atmospheric SO Deposition
2
Rate for Atmospheric Corrosivity Evaluation
1.1 This practice covers and defines conditions for exposure
G92 Practice for Characterization of Atmospheric Test Sites
of metals and alloys to the weather. It sets forth the general
G140 Test Method for Determining Atmospheric Chloride
procedures that should be followed in any atmospheric test. It
Deposition Rate by Wet Candle Method
ispresentedasanaidinconductingatmosphericcorrosiontests
so that some of the pitfalls of such testing may be avoided.As
3. Significance and Use
such, it is concerned mainly with panel exposures to obtain
3.1 The procedures described herein can be used to evaluate
data for comparison purposes.
thecorrosionresistanceofmetalswhenexposedtotheweather,
1.2 The values stated in inch-pound units are to be regarded
as well as to evaluate the relative corrosivity of the atmosphere
as standard. The values given in parentheses are mathematical
at specific locations. Because of the variability and complexity
conversions to SI units that are provided for information only
of weather effects and the industrial and natural factors
and are not considered standard.
influencing the atmospheric corrosivity of a test site, a multi-
1.3 This standard does not purport to address all of the
year exposure period should be considered to minimize their
safety concerns, if any, associated with its use. It is the
influence.Also, as corrosivity may vary at a site from season to
responsibility of whoever uses this standard to consult and
season, exposures should be made either at the same time of
establish appropriate safety and health practices and deter-
the year to minimize variability or these differences should be
mine the applicability of regulatory limitations prior to use.
established by multiple exposures.
3.2 Control specimens should always be employed in
2. Referenced Documents
weathering tests. The control specimens should be from a
2
2.1 ASTM Standards:
material having established weathering characteristics. A sub-
A380 Practice for Cleaning, Descaling, and Passivation of
stantial amount of corrosion data shall have been accumulated
Stainless Steel Parts, Equipment, and Systems
for the control specimens. It is also good practice to retain
D2010/D2010M Test Methods for Evaluation of Total Sul-
samples of all materials exposed so that possible effects of
fation Activity in the Atmosphere by the Lead Dioxide
long-term aging can be measured.
Technique
G1 Practice for Preparing, Cleaning, and Evaluating Corro-
4. Test Sites
sion Test Specimens
4.1 Test sites should be chosen at a number of locations
G33 Practice for Recording Data from Atmospheric Corro-
representative of the atmospheric environments where the
sion Tests of Metallic-Coated Steel Specimens
metals or alloys are likely to be used. If such information is not
G46 Guide for Examination and Evaluation of Pitting Cor-
available, the selection should include sites typical of
rosion
industrial, rural, and marine atmospheres. Test site
G84 Practice for Measurement of Time-of-Wetness on Sur-
characterization, if needed, shall be conducted in accordance
faces Exposed to Wetting Conditions as in Atmospheric
with Practice G92.
Corrosion Testing
4.2 Exposure racks should be located in cleared, well-
drained areas such that the exposed specimens will be sub-
1
This practice is under the jurisdiction of ASTM Committee G01 on Corrosion
jected to the full effects of the atmosphere at the location of the
of Metals and is the direct responsibility of Subcommittee G01.04 on Atmospheric
Corrosion.
test site. Shadows of trees, buildings, or structures should not
Current edition approved Nov. 1, 2015. Published December 2015. Originally
fall on the specimens, and local contamination of the atmo-
approved in 1976. Last previous edition approved in 2010 as G50–10. DOI:
sphereshouldbeavoided,unlessthespecificinfluencesofsuch
10.1520/G0050-10R15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or conditions are intended to be assessed.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4.3 In special cases, the exposure racks may be partially
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. shelteredtoallowaccumulationofcorrosivematerialsfromthe
Copyr
...

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: G50 − 10 G50 − 10 (Reapproved 2015)
Standard Practice for
1
Conducting Atmospheric Corrosion Tests on Metals
This standard is issued under the fixed designation G50; 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*Scope
1.1 This practice covers and defines conditions for exposure of metals and alloys to the weather. It sets forth the general
procedures that should be followed in any atmospheric test. It is presented as an aid in conducting atmospheric corrosion tests so
that some of the pitfalls of such testing may be avoided. As such, it is concerned mainly with panel exposures to obtain data for
comparison purposes.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of
regulatory limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
A380 Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems
D2010/D2010M Test Methods for Evaluation of Total Sulfation Activity in the Atmosphere by the Lead Dioxide Technique
G1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
G33 Practice for Recording Data from Atmospheric Corrosion Tests of Metallic-Coated Steel Specimens
G46 Guide for Examination and Evaluation of Pitting Corrosion
G84 Practice for Measurement of Time-of-Wetness on Surfaces Exposed to Wetting Conditions as in Atmospheric Corrosion
Testing
G91 Practice for Monitoring Atmospheric SO Deposition Rate for Atmospheric Corrosivity Evaluation
2
G92 Practice for Characterization of Atmospheric Test Sites
G140 Test Method for Determining Atmospheric Chloride Deposition Rate by Wet Candle Method
3. Significance and Use
3.1 The procedures described herein can be used to evaluate the corrosion resistance of metals when exposed to the weather,
as well as to evaluate the relative corrosivity of the atmosphere at specific locations. Because of the variability and complexity of
weather effects and the industrial and natural factors influencing the atmospheric corrosivity of a test site, a multi-year exposure
period should be considered to minimize their influence. Also, as corrosivity may vary at a site from season to season, exposures
should be made either at the same time of the year to minimize variability or these differences should be established by multiple
exposures.
3.2 Control specimens should always be employed in weathering tests. The control specimens should be from a material having
established weathering characteristics. A substantial amount of corrosion data shall have been accumulated for the control
specimens. It is also good practice to retain samples of all materials exposed so that possible effects of long-term aging can be
measured.
1
This practice is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subcommittee G01.04 on Atmospheric
Corrosion.
Current edition approved Sept. 1, 2010Nov. 1, 2015. Published October 2010December 2015. Originally approved in 1976. Last previous edition approved in 20032010
as G50–76(2003).G50–10. DOI: 10.1520/G0050-10.10.1520/G0050-10R15.
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.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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G50 − 10 (2015)
4. Test Sites
4.1 Test sites should be chosen at a number of locations representative of the atmospheric environments where the metals or
alloys are likely to be used. If such information is not available, the selection should include sites typical of industrial, rural, and
marine atmo
...