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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ASTM A Intergranular Corrosion Testing and Analysis

The test evaluates the resistance of extra-low-carbon steels to sensitization and intergranular attack from welding or heat treatment processes. It depends on which Practice is selected, but typically ranges from to days for different tests.

The level of corrosion is determined by mass loss. These practices include five intergranular corrosion tests, namely: The weight loss is calculated after each step, and reveals if the sample has been properly heat-treated. Plating and Coating Testing.

The Oxalic Acid test is only used to ensure that no corrosion exists; samples are labeled either “Acceptable” or “Suspect”. This test is used exclusively to determine corrosion in areas high in chromium carbide formations, and is not as effective for intergranular attack caused by other means. Classification of structure then provides either acceptance or further testing required, which typically moves you to one of the next practices.

The chart below comes from the ASTM A standard for selection of the appropriate test by alloy type:. 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.

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To understand intergranular corrosion testing or intergranular attack commonly abbreviated as IGC or IGAit is important to understand what causes the process to occur. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.


Intergranular Attack – ASTM A – Colorado-Metallurgical-Services

Practice E, the Strauss test, is performed to assess attack praactice with chromium-rich carbide formation; it does not detect susceptibility to sigma phase formation. Historical Version s – view previous versions of standard.

This specification is for detecting susceptibility to intergranular attack IGA. All five methods within this specification involve exposing specimens to a chemical mixture designed to encourage corrosive behavior. 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. For example, many low-carbon and stabilized stainless steels e.

This specification covers the standard practices for detecting susceptibility to intergranular attack in austenitic stainless steels. For example, in highly oxidizing solutions, intergranular attack can occur due to intermetallic phases, while attack of carbides may occur somewhat less oxidizing solutions. Carbon and Sulfur Analysis. Wilson Hardness Conversion Chart. Contact us now for pricing or a quote! At the conclusion off the test, specimens are either visually examined or measured for weight loss and compared to an established corrosion rate for that specific material type.

The Oxalic Acid test is also only applicable to corrosion associated with chromium carbide precipitates and is only useful for g material grades.

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 bb. Please specify the maximum allowable corrosion rate and any available data on the sensitizing heat treatment performed. A different ASTM A test method must be used to quantify the level of corrosion or to disqualify a material for use.

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In SEM analysis, intergranular corrosion is clear by the dark lines where the grain boundaries are eaten away. How do you select the right ASTM corrosion testing method for your material? The inch-pound equivalents are in parentheses and may be approximate. Historical Version s – view previous versions of standard Work Item s – proposed revisions of this standard Translated Version s: Due to the variance of attack in different materials, numerous methods Practices B-F are used to assess intergranular corrosion.


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. The oxalic acid test is pracitce used before the Strauss test to determine if a sample is susceptible; samples that a2262 method A will generally show low corrosion rates in the Strauss test.

By using our website you consent to all cookies in accordance with our Cookie Policy. Intergranular simply means that the corrosion is taking place between the grains or crystals, which is where sigma phase or chromium carbides are going to form which makes the material susceptible to IGA.

Some specific hazards statements are given in Link to Active This link will always route to the current Active version of the standard. We provide intergranular corrosion evaluation, salt spray axtm, stress corrosion, and various other methods to simulate exposure of your products or materials to corrosive environments.

Each ASTM A Practice specification includes a list of the grades of stainless steels and v acceptable etch structures for the specific aatm. Classification of the structure after A Practice A pracctice will determine if the material is acceptable or if additional testing is required.

However, when a material is exposed to high temperatures for long periods of time, a process called sensitization may occur. Metals like stainless steels and aluminum contain elements such as niobium and chromium, often integrated because of their natural corrosion resistance.

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