ASTM G92-86(1997)e1

Standard Practice for Characterization of Atmospheric Test Sites

SCOPE
1.1 This practice gives suggested procedures for the characterization of atmospheric test sites. Continuous characteri- ization can provide corrosion data, environmental data, or both which will signal changes in corrosivity of the atmos- pheric environment. This practice can also provide guidance for classification of future test sites.  
1.2 Two methods are defined in this practice for the char- acterization of atmospheric test sites. The methods are iden- tified as characterization Methods A and B. The preferred characterization technique would require using both Method A and B for concurrent data collection.  
1.2.1 Method A is to be used when atmospheric corrosion is monitored on a continuing basis at a test site using specified materials and exposure configurations.  
1.2.2 Method B is specified when atmospheric factors are monitored on a continuing basis.  
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 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: 09-Oct-1997
• Technical Committee: G01 - Corrosion of Metals
• Drafting Committee: G01.04 - Corrosion of Metals in Natural Atmospheric and Aqueous Environments

Relations

• Replaced By: ASTM G92-86(2003) - Standard Practice for Characterization of Atmospheric Test Sites
• Effective Date: 21-Nov-1986
• Referred By: ASTM G112-22 - Standard Guide for Conducting Exfoliation Corrosion Tests in Aluminum Alloys
• Effective Date: 10-Oct-1997
• Referred By: ASTM G50-20 - Standard Practice for Conducting Atmospheric Corrosion Tests on Metals
• Effective Date: 10-Oct-1997
• Referred By: ASTM G140-02(2019) - Standard Test Method for Determining Atmospheric Chloride Deposition Rate by Wet Candle Method
• Effective Date: 10-Oct-1997
• Referred By: ASTM G116-99(2020)e1 - Standard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosion
• Effective Date: 10-Oct-1997

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: G 92 – 86 (Reapproved 1997)
Standard Practice for
Characterization of Atmospheric Test Sites
This standard is issued under the fixed designation G 92; 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 (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Editorial changes were made in December 1997.
1. Scope 3. Summary of Methods
1.1 This practice gives suggested procedures for the char- 3.1 Characterization Method A is to be used when atmo-
acterization of atmospheric test sites. Continuous characteri- spheric corrosion data are to be obtained.
ization can provide corrosion data, environmental data, or both 3.1.1 Corrosion tests to measure the corrosivity of the test
which will signal changes in corrosivity of the atmospheric site should follow the procedure established by Practice G 50.
environment. This practice can also provide guidance for Additional special instructions are identified in this procedure
classification of future test sites. relating to types of materials for corrosion characterization
1.2 Two methods are defined in this practice for the char- tests, time of test exposure, positioning of test specimens,
acterization of atmospheric test sites. The methods are identi- removal of test specimens and proper identification, cleaning
fied as characterization Methods A and B. The preferred practices, and reporting of data.
characterization technique would require using both Method A 3.2 Characterization Method B is to be used when atmo-
and B for concurrent data collection. spheric climatological factors influencing the corrosion of
1.2.1 Method A is to be used when atmospheric corrosion is metals are to be monitored.
monitored on a continuing basis at a test site using specified 3.2.1 Several atmospheric factors which have been identi-
materials and exposure configurations. fied as having significant bearing on the corrosion of metals
1.2.2 Method B is specified when atmospheric factors are include, but are not limited to, sulfur dioxide, chlorides,
monitored on a continuing basis. temperature, humidity, precipitation, time of wetness, and
1.3 This standard does not purport to address all of the atmospheric particulate matter.
safety concerns, if any, associated with its use. It is the 3.3 The preferred technique utilizes both Methods A and B
responsibility of the user of this standard to establish appro- for concurrent data to be collected.
priate safety and health practices and determine the applica- 3.3.1 Should either Method A or B be singled out as the
bility of regulatory limitations prior to use. primary technique to be used on a continuing basis, both
should be used at some point in time to establish a data base.
2. Referenced Documents
The availability of computerized weather stations greatly
2.1 ASTM Standards:
facilitates the collection of reliable atmospheric data.
A 36/A 36M Specification for Carbon Structural Steel
4. Significance and Use
B 6 Specification for Zinc
G 1 Practice for Preparing, Cleaning, and Evaluating Cor- 4.1 This practice gives suggested procedures for character-
rosion Test Specimens ization of atmospheric test sites. It can be useful to researchers,
G 50 Practice for Conducting Atmospheric Corrosion Tests manufacturers, engineering firms, architects, and construction
on Metals contractors to provide corrosion and environmental data, ma-
G 84 Practice for Measurement of Time-of-Wetness on terials selection information, and a materials storage practice.
Surfaces Exposed to Wetting Conditions as in Atmospheric 4.2 This practice does not give specific parameters for
Corrosion Testing classifying the type of test site.
G 91 Practice for Monitoring Atmospheric SO Using the
4 PROCEDURES
Sulfation Plate Technique
5. Method A
5.1 Materials:
This practice is under the jurisdiction of Committee G-1 on Corrosion of Metals
5.1.1 The materials recommended for conducting atmo-
and is the direct responsibility of Subcommittee G01.04 on Atmospheric Corrosion.
Current edition approved Nov. 21, 1986. Published January 1987.
spheric corrosion characterization studies are copper-bearing
Annual Book of ASTM Standards, Vol 01.04.
structural carbon steel (such as Specification A 36/A 36M with
Annual Book of ASTM Standards, Vol 02.04.
Annual Book of ASTM Standards, Vol 03.02.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
G92
0.2 % copper min) and high-purity zinc (Specification B 6 high by the same procedure to ensure a comparative surface finish
grade). following the guidance of Practice G 1. The recommended
* Template contains 126 drilled holes
FIG. 1 Sample Atmospheric Specimen Drill Code Identification Template
5.1.2 Materials recommended are the absolute minimum practice suggested for cleaning is (a) degrease and pickle, if
required to serve as a characterization base for test sites. necessary, to remove grease, mill scale, or other impurities; (b)
Additional materials should be added to meet individual needs. scrub with pumice and britle brush until free of water-break;
Sufficient material should be obtained at the start to insure that (c) dry with towels; and (d) place in a desiccator for 2 h before
an ample supply of the same heat is available to complete the weighing.
characterization test. If tests are on-going and additional 5.2.4 Specimens should be weighed (61.0 mg) and original
materials must be obtained, care should be taken in attempting mass recorded on a data sheet (Table 1). Specific information,
to match material compositions.
such as nominal composition, density, and exposed area should
5.1.3 Sufficient specimens should be prepared to comply also be recorded.
with the specific criteria for the planned characterization test. 5.2.5 Specimens should be stored in a desiccator or sealed in
5.2 Material Preparation: airtight storage bags until the time of exposure.
5.2.1 Test specimens should be sheared to size, for example, 5.3 Exposure of Test Specimens:
100 3 150 mm. 5.3.1 The frequency at which test specimens should be
5.2.2 An identifying code should be assigned to each exposed at a test site is dictated by the specific needs for data.
specimen. Locating a permanent code on each test specimen 5.3.2 Triplicate specimens of each material should be ex-
can be accomplished easily by using a code template (Fig. 1).
posed for each test period.
5.2.2.1 Pre-assignment of codes for a definite test period is 5.3.3 An exposure period of one year is suggested as a
suggested. After a temporary mark is placed on the specimen, minimum, multiple periods should be considered, for example,
a permanent drilled code (a series of 2.5 mm holes) should 3, 6, and 12 months; 1 and 2 years or 1, 2, and 4 years. Shorter
perforate the test specimen.
test periods may be necessary where corrosion is severe and
5.2.3 All test specimens of the same alloy should be cleaned longer test periods where corrosion is less severe.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
G92
TABLE 1 Sample Data Sheet for Atmospheric Corrosion Data
Test Site: Kure Beach (250m lot) Latitude: 34° 008 N
Exposure Dates: 10/7/61 to 10/6/62 Longitude: 77° 558 W
Mass (g) Mass Loss Per Corrosion
Exposure
Material Code Unit Area Rate
Period (days)
Original Final Loss
(mg/m ) (mm/y)
Cu-steel A1-B2 365 196.583 187.332 9.251 2.86 3 10 0.0365
Zinc A2-B2 365 67.521 66.938 0.583 1.84 3 10 0.0026
Test Method Documentation
Steel Zinc
1. Composition (weight %) 0.15 C, 1.0 Mn, 0.01 P, 0.027 S, 0.24 Si, 0.01 Cu, 0.012 Cd, 0.03 Pb, 0.02 Fe,
0.21 Cu, 0.05 Ni, 0.03 Cr, Balance Fe Balance Zn
3 3 3
2. Density (g/cm ) 7.85 g/cm 7.13 g/cm
3. Dimensions (mm) 100 3 150 3 2.00 mm 100 3 150 3 2.00 mm
2 2 2
4. Exposed area (cm ) 322.9 cm 317.7 cm
TABLE 2 Sample Data Sheet for Atmospheric Climatological Data
Test Site: Kure Beach (250m lot) Latitude: 34° 008 N
Dates: 5/1/83 to 5/3/83 Longitude: 77° 558 W
Time of Wetness
Temperature (°C) Relative Humidity (%) Precipitation
Date (h/day)
(mm)
High Low Mean High Low Mean Skyward Groundward
5/1/83 25.6 12.8 19.2 100 56 82 0 12 13
5/2/83 26.1 16.7 21.4 97 56 82 0 10 13
5/3/83 26.7 17.8 22.2 100 60 85 1.3 12 14
5.3.3.1 Consideration should also be given to use of test original mass, composition, original dimensions, and exposed
periods which could allow definition of changes in environ- area and information documented as shown in Table 1.
ment corrosivity occurring during an overall longer term 5.4.3 As each specimen is clearly identified and observa-
evaluation period. For example, exposure of specimens on the tions do
...