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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Measurement of percent elongation is a useful index of embrittlement. G 31 — 72 The phenomenon of forming a protective? If clad alloy specimens are to be used, special attention must be given to ensure that excessive metal is not removed.
A superscript epsilon e indicates an editorial change since the last revision or reapproval. This practice, rather than a standardized procedure, is presented as a guide so that some of the pitfalls of such testing may be avoided.
ASTM G31 – 72() Standard Practice for Laboratory Immersion Corrosion Testing of Metals
A commercial surface may sometimes yield the most signi? However, the calculations must not be based on mass loss except in quali?
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.
Warning—In many cases the corrosion product on the reactive metals titanium and zirconium is a hard and tightly bonded oxide that de? Current edition approved May 1, Corrosion testing by its very nature precludes complete standardization.
For relatively soft metals such as aluminum, magnesium, and copperscrubbing with abrasive powder is not always needed and can mar the astn of the specimen. It is impractical to propose an inflexible standard laboratory corrosion testing procedure for general use, except for material qualification tests where standardization is required. Link to Active This link will always route to the current Active version of the standard.
Referenced Documents purchase separately The documents listed below are referenced within the subject ashm but are not provided as part of the standard. Localized corrosion is reported separately. Methods for chemical cleaning after testing of speci? Excellent references for the use of statistics in corrosion sstm include Ref.
Generally, if cracking is observed on the coupon, it can be taken as positive indication of susceptibility, whereas failure to effect this phenomenon simply means that it did not occur under the duration qstm speci? The density in the constant K cancels out the density in the corrosion rate equation.
A distinction should be made between those occurring underneath the supporting devices concentration cells and those on the surfaces that were freely exposed to the test solution see Guide G For example, a small coupon is not as prone to astk pitting as a large one and it is possible to miss the phenomenon altogether in the corrosion testing of certain alloys, such as the AISI Type series stainless steels in chloride contaminated environments.
The choice of a speci?
These factors include apparatus, sampling, test specimen, test conditions test solution composition, temperature, gas sparging, fluid awtm, solution volume, method of supporting g331 specimens, duration of testmethods of cleaning test specimens, interpretation of results, and calculation of corrosion rates.
Too much surface preparation may remove segregated elements, surface contamination, and so forth, and therefore not be representative. Therefore, short tests on such materials would indicate a high corrosion rate and be completely misleading.
Immersion Corrosion Testing According to ASTM G31 Standard
In many such cases, corrosion rates are established by mass gain rather than mass loss. Any necessary distortion of the test conditions must be considered when interpreting the results.
For other degrees of aeration, the solution should be sparaged with air or synthetic mixtures of air or oxygen with an inert gas. Extraneous effects can be encountered if the air stream impinges on the specimens. The degree of lateral spreading of pits may also be noted. The values given in parentheses are for information only. A method of electrolytic cleaning is described in Practice G 1.
If clad alloys are exposed, special procedures will be required to ensure that only the cladding is exposed, unless the purpose is to test the ability of the cladding to protect cut edges in the test solution.