1 In the appendix, the existing text of the 1.9 and 2.9 are replaced with the
following:
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"Corrosion test: The type of corrosion tests to be applied will depend
on the material, type of weld and the specific cargoes or fuels listed in
the IGC or IGF Codes. The tests should include tests for general corrosion,
intergranular corrosion and stress corrosion. The tests should be carried
out in accordance with, ASTM A262, ASTM G31, ASTM G36, ASTM G58, ASTM G123
or other relevant recognized standards. In the absence of a relevant
recognized standard for the specific cargo or fuel, the test procedures
should align with the general principles of corrosion tests that follow the
recognized standards listed herein.
Acceptance criteria: In accordance with the relevant
recognized standard approved by the Administration for the material's
intended service. In the absence of a relevant recognized standard for the
specific cargoes or fuels, the results should align with other recognized
standards, and projected corrosion rates and test outcomes should be subject
to the satisfaction of the Administration."
2 In the appendix, the following new paragraph 1.10 is added after existing paragraph
1.9:
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"1.10 Corrosion test for ammonia compatibility: The additional test
should be carried out in accordance with the test requirements set out in
appendix 2 to qualify for ammonia service.
Acceptance criteria: should be in accordance with the
acceptance criteria set out in appendix 2."
3 In the appendix, the following new paragraph 2.10 is added after existing paragraph
2.9:
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"2.10 Corrosion test for ammonia compatibility: The additional test
should be carried out in accordance with the test requirements set out in
appendix 2 to qualify for ammonia service.
Acceptance criteria: should be in accordance with the
acceptance criteria set out in appendix 2."
4 Appendix is renamed as appendix 1 and the following new appendix 2 is added after
appendix 1:
"APPENDIX 2
ADDITIONAL COMPATIBILITY TEST REQUIREMENTS FOR AMMONIA SERVICE
The test should be carried out in accordance with a recognized standard such as ASTM
B858. This standard is applicable to copper alloys and not specifically to high
manganese austenitic steel. Consequently, the following additional non-standard test
should be performed:
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.1 Specimens should be prepared in accordance with standards ISO 7539-2 and
ISO 16540. The specimens should be bent, prior to testing, using the four
points bending test under constant strain. The total maximum strain of the
sample should be equal to the yield strength of the material at atmospheric
temperature. Strain gauges should be applied to measure the strain applied.
In the case of welded specimens, strain gauges should be applied to each
side of the welded joint. The sample should be constrained to maintain its
form during testing.
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.2 Two specimens (one welded and one base metal) should each be immersed in
the following four ammonia environments for a period of 30 days:
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.1 liquid phase ammonia environments, obtained by cooling of ammonia
below liquefaction temperature with the following liquid ammonia
compositions:
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.2 gas phase ammonia environments, at ambient temperature and
atmospheric pressure with the following compositions:
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Stress corrosion cracking tests should be performed in
agreement with requirements of standards ISO 7539 and ISO 16540.
.3 Test report should provide all procedures, set-up data, examinations, information
about the environment, in agreement with standard ISO 16540 and include:
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.1 the orientation, types and dimensions of specimens;
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.2 four points bending test set-up data;
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.3 target stress and applied deflection;
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.4 strain measurement procedures;
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.5 loading procedures; and
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.6 test environment.
Test acceptance criteria
After immersion, all specimens should be examined for stress corrosion cracking under
an optical microscope with proper magnification. The location and the number of
cracks should be specified, and a dye penetrant test performed to confirm the
results as necessary. For welded joints, the location of cracks should be described
as located in the base metal, weldment or HAZ. If no superficial crack is observed,
a longitudinal cut should be done at two different locations and a cross section
examination with proper magnification should be performed. The presence of any
corrosion pitting and the maximum depth should be reported. The results should be
approved by the Administration. "