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.
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? Methods for chemical cleaning after testing of speci? 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.
Therefore, short tests on such materials would indicate a high corrosion rate and be completely misleading. A method of electrolytic cleaning is described in Practice G 1. 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. 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.
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?
A metallographic examination may con? Link to Active This link will always route to the current Active version of the standard. It is impractical to propose an inflexible standard laboratory corrosion testing procedure for general use, except for material qualification tests where standardization is required.
A atsm atmospheric seal is required on the test vessel to prevent further contamination. Active view current version of standard. Your comments will receive careful consideration at a asmt of the responsible technical committee, which you may attend. For example, a small coupon is not as prone to exhibit 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.
ASTM NACE / ASTMG31 – 12a Standard Guide for Laboratory Immersion Corrosion Testing of Metals
The values given in parentheses are for information only. This statement must be quali? Chemicals h31 chosen for application to a speci? Calculating Corrosion Rates The coupling of corrosion coupons then yields only qualitative results, as a particular coupon re?
It is v31 responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. If there are any pits, the average and maximum depths of pits asttm determined with a pit gage or a calibrated microscope which can be focused? This guide also emphasizes the importance of recording all pertinent data and provides a checklist for reporting test data.
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. Circular specimens should preferably be cut from sheet and not bar stock, to minimize the exposed end grain.
Preferably, the use of a re? 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. If clad alloy specimens are to be used, special attention must be given to ensure that excessive metal is not removed. Historical Version s – view previous versions of standard.
The density in the constant K cancels out the density in the corrosion rate equation. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. With a thickness of approximately 3 mm 0. This cannot be evaluated by mass loss alone.
For solutions corrosive to glass, suitable metallic or plastic kettles may be employed. Current edition approved May g331, A superscript epsilon e indicates an editorial change since the last revision or reapproval.
Scrubbing t31 a bristle brush and mild abrasive is the most popular of these methods. If this is a factor to be considered in a speci? However, there are cases where this assumption is not valid.
In special cases for example, for aluminum and certain copper alloysa minimum of 24 h storage in a desiccator is recommended.
These factors include specimen preparation, apparatus, test conditions, methods of cleaning specimens, evaluation of results, and calculation and reporting of corrosion rates.
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. The use of towels for drying may introduce an error through contamination of the specimens with grease or lint. The actual time of contact of the metal with the solution must also be taken into account.
Interpretation of Results These factors include oxygen concentration, temperature, rate of? 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.