ASTM G31 PDF
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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Consequently, tests run for long periods are considerably more realistic than those conducted for short durations. The values given in parentheses are for information only.
Masking may also be used to achieve the desired area ratios but may cause crevice corrosion problems. However, there are cases where this assumption is not valid. This standard, rather than a standardized procedure, is presented as a guide so that some of the asttm of such testing may g3 avoided.
Any necessary distortion of the test conditions must be considered when interpreting the results. 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?
This practice also emphasizes the importance of recording all pertinent data asttm provides a checklist for reporting test data. Link to Active This link will always route to the current Active version of the standard. Extraneous effects can be encountered if the air stream impinges on the specimens. For solutions corrosive to glass, suitable metallic or plastic kettles may be employed.
Duplicate strips of low-carbon steel, each 19 by 76 mm 3?
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the aztm 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. 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. A metallographic examination may con? Historical Version s – view previous versions of standard.
It is necessary to evaluate this localized corrosion separately from the overall mass loss. These factors include specimen preparation, apparatus, test conditions, methods of cleaning specimens, evaluation of results, and calculation and reporting of corrosion rates.
Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. A method of electrolytic cleaning is described in Practice G 1.
This cracking occurs under conditions of applied or residual tensile stress, and it may or may not be visible to the unaided eye or upon casual inspection.
However, the absence of cracking should not be interpreted as indicating resistance see 4.
These factors include oxygen concentration, temperature, rate of? Circular specimens should preferably be cut from sheet and not bar stock, to minimize the exposed end grain.
This standard does not purport to address all of the safety concerns, if any, associated with its use. Chemicals are chosen asstm application to a speci? Current edition approved May 1, Molarity and normality are also helpful in de?
Immersion Corrosion Testing According to ASTM G31 Standard
With a thickness of approximately 3 mm 0. A commercial surface may sometimes yield the most signi?
Active view current version of standard. The mechanical property commonly used for comparison is the tensile strength. 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, lead exposed to sulfuric acid corrodes at an extremely high rate at? 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. 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.
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 degree of lateral spreading of pits may also be noted.
The behavior of the specimens in this galvanic couple are compared with that of insulated specimens exposed on the same holder and the galvanic effects noted. 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.
A number in parentheses indicates the year of last reapproval. The use of towels for drying may introduce an error through contamination of the specimens with grease or lint.
Close attention and a more sophisticated evaluation than a simple mass loss measurement are required to detect this phenomenon. If there are any pits, the average and maximum depths of pits are determined with a pit gage or a calibrated microscope which can be focused?
A liquid atmospheric seal is required on the test vessel to prevent further contamination. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
ASTM G Standard Practice for Laboratory Immersion Corrosion Testing of Metals_百度文库
The suggested apparatus is basic and the apparatus is limited only by the judgment and ingenuity of the investigator. It may be desirable to test a surface representative of the material and metallurgical conditions used in practice.
The phenomenon of forming a protective? 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.
With borderline conditions, a prolonged test may be needed to permit breakdown of the passive? The reporting of nonuniform corrosion is discussed below.