Stainless Steels1. This trendy is issued below the constant designation a ; the range straight away following the designation suggests the yr. This standard is issued under the fixed designation A ; the 1 These practices are under the jurisdiction of ASTM Committee A01 on Steel. Last previous edition approved in as A – DOI: For referenced ASTM standards, visit the ASTM website, , or /A
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. Qstm W is used as a screening test to aa763 the necessity, for acceptable specimens, of more extensive testing required by Practices X, Y, and Z.
See Table 1 for a listing of alloys for which Practice W is appropriate. This possibility must be considered in selecting the test method. Combinations of alloys and test methods for which successful experience is available are shown in Table 1. Application of these standard tests to the other ferritic stainless steels will be by speci?
The choices are listed in Table 1. 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. Current edition approved March 1, Originally approved in Last previous edition approved in as A — 93 e1. All other microscopical examinations are of the corroded surface under binocular examination see Section C Preferred criterion, these criteria are the most sensitive for the particular combination of alloy and test.
D Weight loss measurements can be used to detect severely sensitized material, but they are not very sensitive for alloys noted with atm superscript and may not detect slight or moderate sensitization. The ground-glass opening is somewhat over 38 mm 11? The size of the cradles should be such that they can pass through the ground-glass joint of the Erlenmeyer? They should have three or four holes in them to increase circulation of the test solution around the specimen.
NOTE 2—Other equivalent means of specimen support such as glass hooks or stirrups may also be w763. Types,and are nonstabilized grades that are generally not used in the as-welded or sensitized condition in other than mildly corrosive environments. In the annealed condition, they are not subject to intergranular corrosion.
For any studies of IGA on Types,orthe indicated test methods are suggested. Supplementary requirements are noted as required.
ASTM A763 – 15
NOTE 1—No substitution for this equipment may be used. It has been reported that violent boiling resulting in acid astmm can occur. It is important to ensure that the concentration of acid does not a7633 more concentrated and that an adequate number of boiling chips which are resistant to attack by the test solution are present.
Overall length shall be about mm 13 in. If the sample is too thick, multiple specimens should be used. Grind a73 cross section on wet or dry 80 or grit abrasive paper followed by successively? Avoid excessive heat when dry-grinding. Do not use sand- or grit-blasting. All traces of oxide scale formed during heat treatment must be removed.
To avoid scale entrapment, stamp specimens for identi? Specimens with unacceptable microstructures should be subjected to Practices X, Y, or Z to better determine their susceptibility to intergranular attack.
This may be accomplished with the apparatus prescribed in 3. Immersion of the specimen-holding clamp in the etching solution should be avoided. Gas evolved at the electrodes with entrained oxalic acid is poisonous and irritating. Preparation of Test Specimens 4. Additional requirements are noted where necessary. As-welded specimens should be cut so that no more than 13 mm 1?
For very heavy sections, specimens should be prepared to represent the appropriate surface while maintaining reasonable specimen size for convenience in testing. Ordinarily, removal of more material than necessary will have little in?
However, in the special case of surface carburization sometimes encountered, for instance, in tubing when carbonaceous lubricants are employed it may be possible by heavy grinding or machining to remove the carburized layer completely. Such treatment of test specimens is not permissible, except in tests undertaken to demonstrate such surface effects.
A — 93 8. Rinsing Prior to Examination 8. This test detects susceptibility to intergranular attack associated with the precipitation of chromium carbides and nitrides in stabilized and unstabilized ferric stainless steels.
It may also detect the presence of chi or sigma phase in these steels. The test will not differentiate between intergranular attack resulting from carbides and that due to intermetallic phases. The ferric sulfate-sulfuric acid solution may also selectively attack titanium carbides and nitrides in stabilized steels. The alloys on which the test has been successfully applied are shown in Table 1. It may be applied to wrought products and weld metal.
Warning—Protect the eyes and use rubber gloves and apron for handling acid. Add the acid slowly to the water in the Erlenmeyer? NOTE 3—Loss of vapor results in concentration of the acid.
A trip balance may be used. A — 93 FIG. Preparation of Test Specimens If there is an appreciable change in the level, repeat the test with fresh solution and a63 reground specimen. Times for steels not listed in Table 1 are subject to agreement between the supplier and the asmt.
A — 93 The tests can be run without interruption for the time speci? However, if preliminary results are desired, the specimen can be removed at any time for weighing. More asmt sulfate must be added if the total weight loss of all specimens exceeds 2 g.
During the test, ferric sulfate is consumed at a rate of 10 g for each 1 g of dissolved stainless steel. However, several specimens may be tested simultaneously. The number is limited only by the number of glass cradles that can be?
Each sample must be in a separate cradle so that satm samples qstm not touch. See Sections 30 and This test detects susceptibility to intergranular attack associated with the precipitation of chromium carbides or nitrides in unstabilized and a673 ferritic stainless steels. It may also a673 used to evaluate the resistance of high purity or stabilized grades to sensitization astj intergranular attack caused by welding or heat treatments.
It may be zstm to wrought products. For detecting susceptibility to environments known to cause intergranular attack due to these phases use Practice X. An equivalent area of copper shot or chips may be used. The copper should be washed and degreased before use.
Warning—Protect the eyes and face by face shield and use rubber gloves and apron when handling acid. Times for alloys not listed in Table 1 are subject to agreement between the supplier and the purchaser. The tests can be run without interruption. This test detects susceptibility to intergranular attack associated with the precipitation of chromium carbides or nitrides in stabilized and unstabilized ferritic stainless steels.
ASTM A() 铁素体不锈钢晶间腐蚀敏感性检测_百度文库
It may also be used to evaluate the effectiveness of stabilizing element additions Cb, Ti, etc. It may be applied to all wrought products and weld metal. For detecting susceptibility in environments known to cause intergranular attack due to these phases, use Practice X.
It is ideal to have all the specimens in one? The solution volume-to-sample area ratio shall be maintained. NOTE 5—It may be necessary to embed large specimens, such as from heavy bar stock, in copper shot on the bottom of the test? A copper cradle may also be used.
Begin timing the test period when the zstm reaches the boiling point. Atsm 6—Measures should be taken to minimize bumping of the solution when glass cradles are used to support specimens. A small amount of copper shot eight to ten pieces on the bottom of the? Times longer than 24 h should be included in the test report. Fresh test solution would not be needed if the test were to run 48 or 72 h. If ast, adherent copper remains on the specimen, it may be removed by a brief immersion in concentrated nitric acid at room temperature.
The sample is then rinsed in water and dried. Evaluation by Weight Loss Report the corrosion rates as inches of penetration per month, calculated as follows: Shot is preferred for its ease of handling before and after the test. The effect of galvanic coupling between copper and the test specimen may have importance 7. NOTE 7—Conversion factors to other commonly used units for corrosion rates are as follows: Millimeters per month 3 0.