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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These factors include oxygen concentration, temperature, rate of? Link to Active This link will always route to the current Active version of the standard.
Excellent references for the use of statistics in corrosion studies include Ref. A metallographic examination may con? 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. Link to Active This link will always route to the current Active version of the standard.
Any necessary distortion of the test conditions must be considered when interpreting the results. Preferably, the use of a re? For relatively soft metals such as aluminum, magnesium, and copperscrubbing with abrasive powder is not always needed and can mar the surface of the specimen.
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.
Separate and special techniques are employed for the speci? For proper interpretation of the results obtained, the speci? 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 and speci?
Therefore, at least duplicate specimens should normally be exposed in each test. Most tests related to process equipment should be run with the natural atmosphere inherent in the process, such as the vapors of the boiling liquid.
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. G3 degree of lateral spreading of pits may also be noted. Localized corrosion is reported separately.
ASTM G31 – 72() Standard Practice for Laboratory Immersion Corrosion Testing of Metals
Where required, the exhausted constituents should be added or a fresh solution provided during the course of the test. In many such cases, corrosion rates are established by mass gain rather than mass loss. 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.
Interpretation of Results It should be used as a reference to ensure y31 the test will allow generation of data relevant to the application with the minimum of interferences.
NOTE 1—If desired, these constants may also be used to convert corrosion rates from one set of units to another. Methods of Cleaning Specimens after Test 9. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or atsm phonefaxor service astm. The values given in parentheses are for information only. In practice, only alloys of the same general type should be exposed in the testing apparatus. The actual time of contact of the metal with the solution must also be taken into ashm.
It is impractical to propose an in?
Immersion Corrosion Testing According to ASTM G31 Standard
If clad alloy specimens are to be used, special attention must be given to ensure that excessive metal is not removed. If metallic contamination of the stamped area may in? Duplicate strips of low-carbon steel, each 19 by 76 mm 3? 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 signi?
G 31 — 72 Warning—In many cases the corrosion product on the reactive metals titanium and zirconium is a hard and tightly bonded oxide that de? Asrm International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Oxygen saturation is a function of the partial pressure of oxygen in the gas.
This can be accomplished by analysis of the solution after corrosion has occurred. Molarity and normality are also helpful in de? 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.
The phenomenon of forming a protective?
Therefore, short tests on such materials would indicate a high corrosion rate and be completely misleading. A liquid atmospheric seal is required y31 the test vessel to prevent further contamination.