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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Methods for chemical cleaning after testing of specific metals and alloys are described in Practice G 1. Other procedures that require the removal of solid corrosion products between exposure periods will not measure accurately the normal changes of corrosion with time.
Thank you for interesting in our services. Alternatively, the coupon may be rotated through the environment, although it is then difficult to evaluate the velocity quantitatively because of the stirring effects incurred. If the influence of heat transfer effects is specifically of interest, specialized procedures in which the corrosion specimen serves as a heat transfer agent axtm be employed 1.
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. This can be done by chemical treatment picklingelectrolytic removal, or by grinding with a coarse abrasive paper or cloth such as No.
Close attention and a more sophisticated evaluation than a simple mass loss measurement are required to detect this phenomenon. 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.
Careful observation is needed to ensure that pitting does not occur during cleaning. 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 standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. For example, lead exposed to sulfuric acid corrodes at an extremely high rate at first, while building a protective film; then the rates decrease considerably so that further corrosion is negligible.
For solutions corrosive to glass, suitable metallic or plastic kettles may be employed. It is imperative to note that this usually occurs with no significant loss in mass of the test coupon, although certain refractory metals are an exception to these observations. This guide also emphasizes the importance of recording all pertinent data and provides a checklist for reporting test data. If agitation is required, the apparatus can be modified to accept a suitable stirring mechanism, such as a magnetic stirrer.
The amount of possible contamination can be estimated from the loss in mass of the specimen, with proper application of the expected relationships among 1 the area of corroding surface, 2 the mass of the chemical product handled, and 3 the duration of contact of a unit of mass of the chemical product with the corroding surface. Solvents such as acetone, carbon tetrachloride, and alcohol are used to remove oil, grease, or resin and are usually applied prior to other methods of cleaning. 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 practice also emphasizes the importance of recording all pertinent data and provides a checklist for reporting test data. Originally approved in Please help us to share our service with your friends.
Determination of Metal Corrosion Rate by ASTM G Canadian Laboratory – LCS Laboratory Inc.
This can be accomplished by analysis of the solution after corrosion has occurred. These changes should be determined if possible. Special coupons for example, sections of welded tubing may be employed for specific purposes.
A metallographic examination may confirm the presence of stress-corrosion cracking. It should be appreciated that pitting is a statistical phenomenon and that the incidence of pitting may be directly related to the area of metal exposed.
Any necessary distortion of the test conditions must be considered when interpreting the results. Too much surface preparation may remove segregated elements, surface contamination, and so forth, and therefore not be representative.
Location of deposits, variations in types of deposits, or variations in corrosion products are extremely important in evaluating localized corrosion, such as pitting and concentration cell attack.
Interpretation of Results Care should be used to avoid the removal of sound metal. We need your help to maintenance this website.
ASTM G31-72_Laboratory Immersion Corrosion Testing of Metals
The phenomenon of forming a protective film is observed with many corrosion-resistant materials. This practice, rather than a standardized procedure, is presented as a guide so that some of the pitfalls of such testing may be avoided. Size px x x x x