ASTM G_Laboratory Immersion Corrosion Testing of Metals. August 18, | Author: Description. Designation: G 31 – 72 (Reapproved ). Buy ASTM G() Standard Practice for Laboratory Immersion Corrosion Testing of Metals from SAI Global. Offering ASTM G31 corrosion testing + modified tests to fit your needs and budget . Rapid, high-quality service by experts.
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Current edition ashm May 1, Close attention and a more sophisticated evaluation than a simple mass loss measurement are required to detect this phenomenon.
It is necessary adtm evaluate this localized corrosion separately from the overall mass loss. If clad alloy specimens are to be used, special attention must be given to ensure that excessive metal is not removed. G317-2 large surface-to-mass ratio and a small ratio of edge area to total area are desirable.
We are a non-profit group that run this website to share documents. 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.
This cannot be evaluated by mass loss alone.
For example, the accumulation of cupric ions in the testing of copper alloys in intermediate strengths of sulfuric acid will accelerate the corrosion of copper alloys, as compared to the rates that would be obtained if the corrosion products were continually removed. The phenomenon asrm forming a protective film is observed with many corrosion-resistant materials.
This resurfacing may cause some surface work hardening, to an extent which will be determined by the vigor of the surfacing operation, but is not ordinarily significant. It should be observed, however, that galvanic corrosion can be greatly affected by the area ratios of the respective metals, the distance between the metals and the resistivity of the electrolyte.
This can be done by chemical treatment picklingelectrolytic removal, or by grinding with a coarse abrasive paper or cloth such as No. A commercial surface may sometimes yield the most asttm results.
However, there are cases where this assumption is not valid.
Determination of Metal Corrosion Rate by ASTM G31-72. Canadian Laboratory
The total surface area of a circular specimen is given by the following equation: With a thickness of approximately 3 mm 0. This practice, aetm than a standardized procedure, is presented as a guide so that some of the pitfalls of such testing may be avoided. The choice of a specific treatment must be considered on the basis of the alloy to be tested and the reasons for testing. If this is a factor to be considered in a specific test, the solution should be completely aerated or deaerated in accordance satm 8.
This can be accomplished by analysis of the solution after corrosion has occurred.
Determination of Metal Corrosion Rate by ASTM G Canadian Laboratory – LCS Laboratory Inc.
Link to Active This link will always route to the current Active version of the standard. There are a number of other special types of phenomena of which one must be aware in the design and interpretation of corrosion tests. This standard does not purport g31-27 address all of the safety concerns, if any, associated with its use. Historical Version s – view previous versions of standard.
A distinction should be made between those occurring underneath the supporting devices concentration cells and those on the surfaces that were g31-772 exposed to the test solution see Guide G The corrosion rate can be calculated from the concentration of the matrix metal found in the solution and it can be compared to that determined from the mass loss of the specimens. This standard, rather than a standardized procedure, is presented as a guide so that some of the pitfalls of such testing may be avoided.
Circular specimens should preferably be cut from sheet and not bar stock, to minimize the exposed end grain. Most tests related to process equipment should be run with the natural atmosphere inherent in the process, such aetm the vapors of the boiling liquid. These changes t31-72 be determined if possible. Masking may also be asmt to achieve the desired area ratios but may cause crevice corrosion problems. Methods of Cleaning Specimens after Test 9.
Please fill this form, we will try to respond as soon as possible. Constant K in Corrosion Rate Equation 3. These factors include specimen preparation, apparatus, test conditions, methods of cleaning specimens, evaluation of results, and calculation and reporting of corrosion rates.
The surface finish to be encountered in service may be more appropriate for some testing. If metallic contamination of the stamped area may influence the corrosion behavior, chemical cleaning must be employed to remove any traces of foreign particles from the surface of the coupon for example, by immersion of stainless steel coupons in dilute nitric acid following stamping with steel dies.
Active view current version of standard.
We need your help to maintenance this website. Using the b31-72 units for T, A, W, and D, the corrosion rate can be calculated in a variety of units with the following appropriate value of K: Please copy and paste this embed script to where you want to embed Embed Script.