ASTM G36-94(2013)
(Practice)Standard Practice for Evaluating Stress-Corrosion-Cracking Resistance of Metals and Alloys in a Boiling Magnesium Chloride Solution
Standard Practice for Evaluating Stress-Corrosion-Cracking Resistance of Metals and Alloys in a Boiling Magnesium Chloride Solution
SIGNIFICANCE AND USE
5.1 For most applications, this environment provides an accelerated method of ranking the relative degree of stress-corrosion cracking susceptibility for stainless steels and related alloys in aqueous chloride-containing environments. Materials that normally provide acceptable resistance in hot chloride service may crack in this test. The test may not be relevant to stress-corrosion cracking in polythionic acid or caustic environments.
5.2 Resistance to stress-corrosion cracking in boiling magnesium chloride (155.0°C (311.0°F)) should, where possible, be correlated to resistance in service for the materials of interest. However, such correlations may not always be possible.
5.3 Boiling magnesium chloride may also cause pitting of many stainless alloys. This leads to the possibility of confusing stress-corrosion failures with mechanical failures induced by corrosion-reduced net cross sections. This danger is particularly great when small cross section samples, high applied stress levels, long exposure periods, stress-corrosion resistant alloys, or a combination thereof are being used. Careful examination is recommended for correct diagnosis of the cause of failure.
SCOPE
1.1 This practice describes a procedure for conducting stress-corrosion cracking tests in a boiling magnesium chloride solution. Although this test may be performed using various concentrations of magnesium chloride, this procedure covers a test solution held at a constant boiling temperature of 155.0 ± 1.0°C (311.0 ± 1.8°F). The boiling points of aqueous magnesium chloride solutions at one atmosphere pressure as a function of concentration are shown graphically in Fig. 1.2 A suggested test apparatus capable of maintaining solution concentration and temperature within the prescribed limits for extended periods of time is also described herein.3
1.2 The boiling magnesium chloride test is applicable to wrought, cast, and welded stainless steels and related alloys. It is a method for detecting the effects of composition, heat treatment, surface finish, microstructure, and stress on the susceptibility of these materials to chloride stress corrosion cracking.4
1.3 This practice is concerned primarily with the test solution, which may be used with a variety of stress corrosion test specimens, surface finishes, and methods of applying stress.
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. See Section 7 for specific safety precautions.
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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: G36 − 94 (Reapproved 2013)
Standard Practice for
Evaluating Stress-Corrosion-Cracking Resistance of Metals
1
and Alloys in a Boiling Magnesium Chloride Solution
ThisstandardisissuedunderthefixeddesignationG36;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. See Section 7 for
1.1 This practice describes a procedure for conducting
specific safety precautions.
stress-corrosioncrackingtestsinaboilingmagnesiumchloride
solution. Although this test may be performed using various
2. Referenced Documents
concentrations of magnesium chloride, this procedure covers a
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2.1 ASTM Standards:
test solution held at a constant boiling temperature of 155.0 6
D1193Specification for Reagent Water
1.0°C (311.0 6 1.8°F). The boiling points of aqueous magne-
G1Practice for Preparing, Cleaning, and Evaluating Corro-
sium chloride solutions at one atmosphere pressure as a
sion Test Specimens
2
function of concentration are shown graphically in Fig. 1. A
G15Terminology Relating to Corrosion and CorrosionTest-
suggested test apparatus capable of maintaining solution con-
6
ing (Withdrawn 2010)
centration and temperature within the prescribed limits for
G30 Practice for Making and Using U-Bend Stress-
3
extended periods of time is also described herein.
Corrosion Test Specimens
1.2 The boiling magnesium chloride test is applicable to
3. Terminology
wrought, cast, and welded stainless steels and related alloys. It
is a method for detecting the effects of composition, heat
3.1 Definitions—For definitions of terms used in this prac-
treatment, surface finish, microstructure, and stress on the
tice see Terminology G15.
susceptibility of these materials to chloride stress corrosion
4 4. Summary of Practice
cracking.
4.1 A predetermined quantity of reagent grade magnesium
1.3 This practice is concerned primarily with the test
chloride and some distilled water are added to a container.The
solution, which may be used with a variety of stress corrosion
container and contents, with thermometer and condenser
test specimens, surface finishes, and methods of applying
affixed, are placed on a source of heat. When the magnesium
stress.
chloride solution boils, it is adjusted to maintain the desired
1.4 This standard does not purport to address all of the
concentration and boiling point through the addition of small
safety concerns, if any, associated with its use. It is the
quantities of either water or salt.
responsibility of the user of this standard to establish appro-
4.2 After the solution has stabilized at the desired boiling
pointforthetest,thestressedspecimensareadded.Depending
1
This practice is under the jurisdiction ofASTM Committee G01 on Corrosion
upon the intent of the test, the specimens should be given
of Metals and is the direct responsibility of Subcommittee G01.06 on Environmen-
periodic inspections. If the duration of test exceeds 7 days, the
tally Assisted Cracking.
solution should either be changed or the suggested or similar
CurrenteditionapprovedMay1,2013.PublishedJuly2013.Originallyapproved
in 1973. Last previous edition approved in 2006 as G36–94 (2006). DOI:
test apparatus used.
10.1520/G0036-94R13.
2
Available data on the relationship of concentrations and boiling points of
5. Significance and Use
magnesium chloride solutions are critically reviewed and supplemented by I. B.
5.1 For most applications, this environment provides an
Casale in “Boiling Points of Magnesium Chloride Solutions—TheirApplication in
Stress Corrosion Studies,” Corrosion , Vol 23, 1967, pp. 314–17.
accelerated method of ranking the relative degree of stress-
3
The apparatus and test procedures for maintaining constant boiling tempera-
corrosioncrackingsusceptibilityforstainlesssteelsandrelated
tures of magnesium chloride solutions for stress corrosion tests are described by M.
A. Streicher and A. J. Sweet in Corrosion, Vol 25, 1969, pp. 1–6.
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The use of concentrated magnesium chloride solutions for determining the For referenced ASTM standards, visit the ASTM website, www.astm.org, or
susceptibility to stress corrosion cracking of austenitic and ferritic stainless steels contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and related nickel-base alloys was first described by M. A. Scheil, Symposium on Standards volume information, refer to the standard’s Document Summary page on
Stress Corrosion Cracking of Metals, ASTM STP 64, ASTM, 1945, p. 395. the ASTM website.
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