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?
Immersion Corrosion Testing According to ASTM G31 Standard
Methods for chemical cleaning after testing of speci? 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.
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 values given in parentheses are for information only.
The choice of a speci? With borderline conditions, a prolonged test may be needed to permit breakdown of the passive? This guide also emphasizes the importance of recording all pertinent data and provides a checklist for reporting test data.
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? 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. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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 statement must be quali?
ASTM NACE / ASTMG31 – 12a Standard Guide for Laboratory Immersion Corrosion Testing of Metals
Historical Version s – view previous versions of standard. Any necessary distortion of the test conditions must be considered when interpreting the results. Masking may asttm be used to achieve the desired area ratios but may cause crevice corrosion problems. A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. Ast, 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.
If cleaning deposits for example, scouring powder remain or lack of complete dryness is suspected, then recleaning and drying is performed until a constant mass is attained. In many such cases, corrosion rates are established by mass gain rather than mass loss. Warning- In many cases the satm product on the reactive metals titanium and zirconium is a hard and tightly bonded oxide that defies removal axtm chemical or ordinary mechanical means.
The coupling of corrosion coupons then yields only qualitative results, as a particular coupon re?
These factors include specimen preparation, apparatus, test conditions, methods of cleaning specimens, evaluation of results, and calculation and reporting of corrosion rates. There are a number of other special types of phenomena of which one must be aware in the design and interpretation of corrosion tests.
Oxygen saturation is a function of the partial pressure of oxygen in the gas. Using the satm units for T, A, W, and D, the corrosion rate can be calculated in a variety g331 units with the following appropriate value of K: However, the absence of cracking should not be interpreted as indicating resistance see 4.
The procedures for determining these values are shown in detail in Test Methods E 8. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Cupric ions may also exhibit a passivating wstm upon stainless steel coupons exposed at the same time.
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. Circular specimens should preferably be cut from sheet and not bar stock, to minimize the exposed end grain. 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.
Excellent references for the use of asrm in corrosion studies include Ref.
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.
Measurement of percent elongation is a useful index wstm embrittlement. This cannot be evaluated by mass loss alone. Care should be used to avoid the removal of sound metal.