March 4, 2019


ASTM a Test, Intergranular Corrosion, IGC, ASTM A Practice, Testing, India – Download as PDF File .pdf), Text File .txt) or read online. ASTM A Practice A test (Oxalic acid test). The oxalic acid etch test is rapid and nondestructive, but not quantitative. It is a rapid etching procedure and . Abstract. A detailed study of AISI and stainless steels (SSs) has been conducted to correlate the degree of sensitization (DOS) measured by the.

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This abstract is a brief summary of the referenced standard. See Appendix X1 for information regarding test selection. How do you select the right ASTM corrosion testing method for your material?

The test evaluates the resistance of extra-low-carbon steels to sensitization and intergranular attack from welding or heat treatment processes. The Huey test works well to analyze chromium depleted regions and intermetallic precipitates, such as sigma phase, and is also used for materials in strongly oxidizing environments such as nitric w262.

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Work Item s – proposed revisions of this standard. The Strauss test is commonly used to evaluate the heat-treatment of as-received material, the effectiveness of alloying additions of elements such as Nb and Ti, or the effectiveness of reducing carbon content to resist practkce attack. It is informational only and not an official part of the standard; the full text of qstm standard itself must be referred to for its use and application.

The ASTM A tests can determine if the proper heat treatment was performed or if the alloys are in danger of intergranular corrosion occurring in use. Intergranular corrosion occurs as a result of precipitation of nitridescarbidesand other intermetallic phasessuch as sigma phase, that occurs along the grain boundaries.

A recent publication on intergranular corrosion. Classification of the structure after A Practice A analysis will determine if the material is acceptable or if additional testing is required.

ASTM A Intergranular Corrosion Testing and Analysis

These tests are often run as a qualification test to ensure each batch of stainless steel is properly prepared. 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 practicee chromium carbides at grain boundaries. Our knowledgeable scientists have the experience and expertise necessary to determine the most appropriate intergranular attack testing methods for your material while providing actionable results you can rely on.


All austenitic stainless steels should meet aa262 requirement, if proper annealing took place. This practice includes boiling the sample for 24 to hours in the solution above, and measures the materials performance quantitatively. Wilson Hardness Conversion Chart. This method is a hour boiling prxctice for “as received” specimens of stainless steel. Choosing an Intergranular Corrosion Test Method Since high temperature processing such as heat pgactice is a common practice, many manufacturers wish to perform intergranular corrosion qualification testing on each batch, to ensure that the material has been processed correctly and does not show signs of corrosion susceptibility.

Practice A is a rapid screening examination of the microstructure to quickly determine if the structure is certain to be free of susceptibility to rapid intergranular attack. By using our website you consent to all cookies in accordance with our Cookie Policy. We provide intergranular corrosion evaluation, salt spray testing, stress corrosion, and various other methods to simulate exposure of your products or materials to corrosive environments.

Discover perspectives, resources, and advice from our world-leading Engaged Experts. Share on Tumblr Print. Due to the variance of attack in different materials, numerous methods Practices B-F are used to assess intergranular corrosion. In many cases we can reduce that to as little as 24 hours more than the required testing time if you need fast results.

Link to Active This link will always route to the current Active version of the standard.

Choosing the correct method s rely on a complete understanding of your material and processes, as well as the concept of corrosion itself. If you are not sure, please contact us for assistance.

Intergranular simply means that the corrosion is taking place between the grains or crystals, practicw is where sigma phase or chromium carbides are going to form which makes the material susceptible to IGA.

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. The samples are weighed at each interval to determine mass loss and degree of susceptibility to intergranular attack.


Please refer to the specification for more details. The test uses a visual inspection of the surface of the bent specimen to determine pass or fail. Rockwell or Superficial Hardness.

A bend test followed by a visual or micro-examination are used to determine “Pass” or “Fail” of test specimens.

Intergranular Corrosion Testing: An Overview of ASTM A262

If materials with incorrect heat treatment enter service, they are liable to crack 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. If the structure is acceptable no additional testing is required. Strauss test specimens are boiled in a Copper Sulfate – Sulfuric Acid mixture for 15 hours.

The oxalic acid test is commonly used before the Strauss test to determine if a sample is susceptible; samples that pass method A will generally show low corrosion rates in the Strauss test.

ASTM A Testing: An Overview of Intergranular Corrosion | Element

There is several cause for SCC, Chloride is the leading cause of transgranular cracking or attack. Sensitization causes the grain boundaries of a material to precipitate, creating carbide deposits and causing the material to be susceptible to intergranular attack.

In everyday applications, corrosion varies by materials and solutions. Learn more about our laboratories – where they are located; the unique capabilities they have and how they can help you solve your technical and commercial challenges. In SEM analysis, intergranular corrosion is clear by the dark lines where the grain boundaries are eaten away.

Typical examination magnification is X to X. It depends on which Practice is selected, but typically ranges from to days for different tests. The samples are etched after metallographic preparation for cross-sectional examination which is thoroughly viewed with a traverse from inside to outside diameters of rods and tubes, from face to face on plates, and across all prachice such as weld ;ractice, weld-affected zones, and base plates on specimens containing welds.

The level of corrosion is determined by mass loss. The Oxalic Acid test is also only applicable to corrosion associated with chromium carbide precipitates and is only useful for specific material grades.