Designation: A – 10 Standard Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels1 This standard is. ASTM, 16 p, A Standard Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels Abstract This. ASTM A – Standard Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels Thanks in advance.
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To obtain the correct current density: There may be restrictions placed on specimen size by the testing apparatus. However, if preliminary results are desired, the specimen can be removed at any time for weighing. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. It is the responsibility of the user of this standardto establish appropriate safety and health practices and determinethe applicability of regulatory limitations prior touse.
This test may be used to evaluate the heat treatment accorded as-received material. Intergranular corrosion occurs as a result of precipitation of nitridescarbidesand other intermetallic phasessuch as sigma phase, that occurs along the grain boundaries.
Practice E, the Strauss test, is performed to assess attack associated with chromium-rich carbide formation; it does not detect susceptibility to sigma phase formation.
NOTE 1—The variable resistance and the ammeter are placed in the circuit to measure and control the current on the specimen to be etched. Also, by mutual agreement, a combination of one h period and two h periods not necessarily in that order instead of?
A copper cradle may also be used. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but a2621-0 not provided as part of the standard. It has been reported that violent boiling resulting in acid spills can occur. Due to the variance of attack in different materials, numerous methods Practices B-F are used to assess intergranular corrosion. Preparation of Test Specimens 5.
The inch-pound equivalents are in parentheses and may be approximate. A — z262-10 One of these consists of a 1-L Erlenmeyer? The number 3 or 4 is limited only by the number a262-1 glass cradles that can be? When the available length is less than 1 cm, a full cross section should be used. Summary of Practice Please share this page: C Ring sections are not? NOTE 7—Loss of vapor results in concentration of the acid.
The tests can be run without interruption for h. However, if with this shorter test procedure the rate of attack in the third period should exceed that in either the?
ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date. Each ASTM A Practice specification includes a list of the grades of stainless steels and the acceptable etch structures for the specific alloys.
If more than one of the specimens tested in the same container fail to pass the test, it is necessary to retest all specimens in separate containers, since excessive corrosion of one specimen asym result in accelerated corrosion of the other specimens tested with it. The ASTM A tests aastm determine if the proper heat treatment was performed or if the alloys are in danger of intergranular corrosion occurring in use.
Nitric Acid Test Solution Begin timing the test period when the solution reaches the boiling point. Such specimens are acceptable without testing in the ferric sulfatesulfuric acid test.
However, in the special case of surface carburization sometimes encountered, for instance, Copyright by ASTM Int’l all rights reserved ; Wed May 19 The test is generally performed for acceptance of materials, but not sufficient for rejection of materials. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.
The rate of heating depends on the total current ammeter reading passing through the cell.
The latter may be formed in molybdenum-bearing and in stabilized grades of austenitic stainless steels and may or may not be visible in the microstructure. This solution may be prepared by adding distilled water to concentrated nitric acid reagent grade HNO3, sp gr 1. The purpose of these treatments is to remove any surface contamination that may not be accomplished by the regular asym method and which may increase a262-100 apparent weight loss of the specimen during the early part of the test.
Heavy specimens may require bending in a?
The second type of container is the so-called multi-sample testing apparatus 5 which was designed to permit the testing of a large number of specimens simultaneously by providing for replacement of the acid in contact with the specimens several times per hour with redistilled acid. NOTE 4—To detect susceptibility to intergranular attack associated with sigma phase in austenitic stainless steels containing molybdenum, the nitric acid test, Practice C, should be used.
Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. A a2621-0 10 determine the susceptibility of austenitic stainless steels to intergranular attack. In SEM analysis, intergranular corrosion is clear by the dark lines where the grain boundaries are eaten away. This may cause rapid intergranular attack in the nitric acid test. The pits which now appear completely black are end grain pits.
This practice includes boiling the sample for 24 to hours in the solution above, and measures the materials performance quantitatively. The etch structure types used to classify the specimens are: Protect the eyes and face by face shield and use rubber gloves and apron when handling acid.