The ASTM G Standard Guide for the “Examination and Evaluation of Pitting ASTM Standard G15, Standard Terminology Relating to Corrosion and. Buy ASTM G() Standard Guide for Examination and Evaluation of Pitting Corrosion from SAI Global. ASTM G(). Standard Guide for Examination and Evaluation of Pitting Corrosion. standard by ASTM International, 05/01/ This document has.
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Standard Guide for Examination and Evaluation of Pitting Corrosion
Pitting corrosion is highly localized corrosion occurring on a metal surface. Pitting is commonly observed on surfaces with little or no general corrosion.
Pitting typically occurs as a process of local anodic dissolution where metal loss is exacerbated by the presence of a small anode and a large cathode. Pitting in Aluminum. The localized pitting corrosionwas produced in aluminum floats on a storage tank roof.
The exposure conditions involved hydrocarbon fluids following an initial hydrotest. The pitting occurred in astk absence of chlorides at a near neutral pH where aluminum would be expected to exhibit good resistance to corrosion.
ASTM G46 – 94() Standard Guide for Examination and Evaluation of Pitting Corrosion
Sulfur corrosion products were found in the pits and sulfate reducing bacteria were suspected resulting from prolonged exposure to hydrotest water. Prevention or Remedial Action.
For more severe pitting service in some environments Ti – and Zr – alloys may also be appropriate. Evaluation of Pitting Corrosion.
The extent of pitting corrosion can vary astn depending on the exposure conditions and surface condition of the material. Commonly used methods to determine the pitting corrosion resistance are.
Electrochemical measurements should always be supplemented by such techniques to obtain the most accurate indications. Pitting in Aluminum – The localized pitting corrosionwas produced in aluminum floats on a storage tank roof.
Norma ASTM G()
Deaeration of aerated environments to reduce localized corrosion through elimination of oxygen concentration cell mechanism. ASTM G – test methods for pitting and crevice corrosion resistance of stainless steels and related alloys by the use of ferric chloride solution. ASTM G – standard reference test method for making poteniostatic and potentiodynamic anodic polarization measurements.
ASTM G – test method for conducting cyclic potentiodynamic polarization measurements for localized corrosion susceptibility of iron, nickel or cobalt based alloys. ASTM G – modified salt spray fog testing. Evaluation of Pitting Corrosion The extent of pitting corrosion can vary greatly depending on the exposure conditions and surface condition of the material.
Commonly used methods to determine the pitting corrosion resistance are Simple exposure of corrosion coupons to standardized environments of 4g6 severity ASTM G Evaluaiton of coupons and metal surfaces with standardized techniques to categorize the nature of the pitting attack ASTM G Use of electrochemical techniques ASTM G61 to characterize the current-potential polarization behavior of the material in specific service environments to identify materials susceptible to pitting attack.