ASTM a Test, Intergranular Corrosion, IGC, ASTM A Practice, Testing, India Ferric Sulfate – Sulfuric Acid, ASTM A – Practice B (Streicher Test). ASTM A practice – Free download as Excel Spreadsheet .xls /.xlsx), PDF File .pdf), Text File .txt) or read online for free. ASTM A Practice B test. In this test a sample of surface area cm. 2 is exposed for a period of hours to boiling solution of 50% H2SO4 + %.
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Classification of structure then provides either acceptance or further testing required, which typically moves you to one of the next practices. All five methods within this specification involve exposing specimens to a chemical mixture designed to encourage corrosive behavior. It depends on which Practice is selected, but typically ranges from to days for different tests.
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. Asmt inch-pound equivalents are in parentheses and may be approximate.
Carbon and Sulfur Analysis.
ASTM A Intergranular Corrosion Testing and Analysis
This practice includes boiling the sample for 24 to hours in the solution above, and measures the materials performance quantitatively.
Plating and Coating Testing. Intergranular corrosion occurs as a result of precipitation of nitridescarbidesand other intermetallic phasessuch as sigma phase, that occurs along the grain boundaries.
If materials with incorrect heat treatment ;ractice service, they are liable to satm or fail by intergranular corrosion IGC much more rapidly than properly treated materials; ASTM A is a screening test to help find batches that are incorrectly processed.
Please share this page: Duplicate samples from both sides of a sheet sample are evaluated to determine if carburization results in intergranular attack.
View more articles about Aerospace Oil and Gas Transportation. Each ASTM A Practice specification includes a list of the grades of stainless steels and the acceptable etch structures for the specific alloys.
The bent asm are examined at low magnification, where the appearance of cracks or fissures indicate intergranular attack. In SEM analysis, intergranular corrosion is clear by the dark lines where the grain boundaries are eaten away.
The test uses a visual inspection of the surface of the bent specimen to determine pass or fail.
All austenitic stainless steels should meet this requirement, if proper annealing took place. G2MT Labs is one of the few labs to offer all five ASTM A corrosion testing practices, as well as the expertise to help you determine which tests to use, what to do if a test fails, and other corrosion consulting as needed. Classification of the structure after A Practice A analysis will determine if the material is acceptable or if additional testing is required.
Based on your materials, application, and requirements, the other 4 methods provide specific focuses. ASTM A testing is a popular method of choice due to the variety of practices available and the relatively short turnaround for results.
The samples are weighed at each interval to determine mass loss and degree of susceptibility to intergranular attack.
This abstract is a brief ast of the referenced standard. Work Item s – proposed revisions of this standard. This simple etching technique is used as a quick screening method to ensure that a material is free of intergranular corrosion susceptibility. In many cases we can reduce that to as little as 24 hours more than the required testing time if you a2662 fast results. Historical Version s – view previous versions of standard. If you are not sure, please contact us for assistance.
Intergranular Corrosion Testing: An Overview of ASTM A262
Please specify the maximum allowable corrosion rate and any available lractice on the sensitizing heat treatment performed. Historical Version s – view previous versions of standard Work Item s – proposed revisions of this standard Translated Version s: Strauss test specimens are boiled in a Copper Sulfate – Sulfuric Acid mixture for 15 hours. The etch structure types used to classify the specimens are: A bend test followed by a visual or micro-examination are used to determine “Pass” or “Fail” of test specimens.
Methods for preparing the test specimens, rapid screening tests, apparatus setup and testing procedures, and calculations and report contents are described for each testing practice.