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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Normally, s262-10 maximum convenient weight of specimen is about g. In everyday applications, corrosion varies by materials and solutions. Also needed are the following: These tests are often run as a qualification test to ensure each batch of stainless steel is properly prepared. The presence or absence of asstm attack in this test is not necessarily a measure of the performance of the material in other corrosive environments.
In SEM analysis, intergranular corrosion is clear by the dark lines where the grain boundaries are eaten away. The first and fastest step is the ASTM A Practice A, a rapid same-day screening method in Oxalic acid to determine the susceptibility to intergranular corrosion. Practice F, is a hour weight-loss based analysis that provides a quantitative measure of the materials performance, and is commonly used to analyze as-received stainless steels. NOTE 17—Conversion factors to other commonly used units for corrosion rates are as follows: Rapid Screening Test 9.
Up to 6 mm? Experience has shown that the presence of even small amounts of hydro? However, if with this shorter test procedure the rate of attack in the third period should exceed that in either the? This test may be used to evaluate the heat treatment accorded as-received material.
Over 5 mm 3?
If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. Such treatment of test specimens is not permissible, except in tests undertaken to demonstrate such surface effects.
It is generally completed by bringing the two ends together in the vise. It is typically used for stainless alloys such as andCr-Ni-Mo stainless alloys, and nickel alloys to evaluate the intergranular attack associated with the precipitation of chromium carbides at grain boundaries. The length of time used for this sensitizing treatment determines the maximum permissible corrosion rate in the nitric acid test.
If not 15 h, the test time shall be speci? Furthermore, in the case of bar, wire, and tubular products, the proportion of the total area represented by the exposed cross section may in? It may be applied to wrought products including tubescastings, and weld metal.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Last previous edition approved in as A — 02a A recent publication on intergranular corrosion.
There may be restrictions placed on specimen size by the testing apparatus. If any cross-sectional dimension is less than 1 cm, a minimum length of 1 cm should be polished. Permission rights to photocopy the standard may also be secured from the ASTM website www. A — 10 completely.
An electrically heated hot plate is satisfactory for this purpose. However, if preliminary results are desired, the specimen can be removed at any time for weighing. In many cases we can reduce that to as little as 24 hours more than the required a226-10 time if you need fast results.
Aa262-10, any susceptibility to intergranular attack is readily detected by pronounced ditches. Scale should be removed from the area to be etched by grinding to an or grit? D Must be tested in nitric acid test when destined for service in nitric acid.
Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. 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. The test evaluates the resistance of extra-low-carbon steels to sensitization and intergranular attack from welding or heat treatment processes.
E To date, no data have been published on the effect of sigma phase on corrosion of AISI in this test. NOTE 2—All photomicrographs were made with specimens that were etched under standard conditions: 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. NOTE 3—See Practice A for information on the most appropriate of the several test methods available for the evaluation of speci?
A — 10 boiling test solution.
The test does not provide a basis for predicting resistance to other forms of corrosion, such as general corrosion, pitting, or stresscorrosion cracking. Steps between austenite matrix and ferrite pools. These lists may contain grades of steels in addition to those given in the rectangles. For very heavy sections, specimens should be machined to represent the appropriate surface while maintaining reasonable specimen size for convenience in testing.
The purpose of these treatments is to remove any surface contamination that may not be accomplished by the regular cleaning method and which may increase the apparent weight loss of the ashm during the early part of the test. The chart below comes from the ASTM A standard for selection a262-01 the appropriate test by alloy type:. B One surface shall be an original surface of awtm material under test and it shall be on the outside of the bend. These specimens are identi?
It is ideal to have all the specimens in one?
Excessive corrosion may often be atm by changes in the color of the test solution, and it may be appropriate to provide separate containers for such specimens without waiting until the end of the test period. Originally approved in The bend radius shall not be less than that required for mechanical testing in the appropriate material speci? Fresh test solution would not be needed if the test were to run 48 or even 72 h.