ASTM G_Laboratory Immersion Corrosion Testing of Metals – Free download as PDF File .pdf), Text File .txt) or read online for free. ASTM G Other ASTM procedures for laboratory corrosion tests are tabulated in the Appendix. NOTE 1—Warning: In many cases the corrosion product on the reac-. ASTM G Standard Practice for Laboratory Immersion Corrosion Testing of Metals_能源/化工_工程科技_专业资料. 暂无评价|0人阅读|0次.
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If this is a factor to be considered in a speci? Any necessary distortion of the test conditions must be considered g311 interpreting the results. Care should be used to avoid the removal of sound metal.
The mass loss during the test period can be used as the principal measure of corrosion. Molarity and normality are also helpful in de?
However, the calculations must not be based on mass loss except in quali? The degree of lateral awtm of pits may also be noted.
ASTM G31 – 72() Standard Practice for Laboratory Immersion Corrosion Testing of Metals
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.
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. G 31 — 72 A superscript epsilon e indicates an editorial change since the last revision or reapproval.
It should be used as a reference to ensure that the test will allow generation of data relevant to the application with the minimum of interferences. The actual time of contact of the metal with the solution must also be taken into account.
A large surface-to-mass ratio and a small ratio of edge area to total area are asrm. The suggested apparatus is basic and the apparatus is limited only by the judgment and ingenuity of the investigator. The values given in parentheses are for information only.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.
Other g311 that require the removal of solid corrosion products between exposure periods will not measure accurately the normal changes of corrosion with time.
If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.
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. Current edition approved May 1, Duplicate asmt of low-carbon steel, each 19 by 76 mm 3? Excellent references for the use of statistics in corrosion studies include Ref.
The others are used principally as a supplement to remove heavily encrusted corrosion products before scrubbing. Your comments will atm careful consideration at a meeting of astn responsible technical committee, which you may attend. In special cases for example, for aluminum and certain copper alloysa minimum of 24 h storage in a desiccator is recommended.
With borderline conditions, a prolonged test may t31 needed to permit breakdown of the passive? Special coupons for example, sections of welded tubing may be employed for speci? For example, lead exposed to sulfuric acid corrodes at an extremely high rate at? These ratios can be achieved through the use of square or circular specimens of minimum thickness.
astj This can be accomplished by analysis of the solution after corrosion has occurred. These factors include oxygen concentration, temperature, rate of? Occasional exceptions, in which a large difference is observed, can occur under conditions of borderline passivity of metals or alloys that depend on a passive? 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.
Separate and special techniques are employed for the speci? If clad alloy specimens are to be used, special attention must be given to ensure that excessive metal is not removed. 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. However, some of the corrosion products usually adhere to the specimen as a scale and the corrosion rate calculated from the metal content in the solution is not always correct.
Proper ultrasonic procedures are an acceptable alternate.