ASTM G46 Examination and Evaluation of Pitting Corrosion

ASTM G46 Test Scope:

The ASTM G46 can evaluate the level of pitting in a service application where the remaining life of a metal structure must be predicted. This test is used for a variety of purposes, including evaluating alloy performance, establishing if an alloy is resistant to the environment, and analyzing how environmental variables, such as corrosion inhibitors, affect or prevent pitting.

ASTM G46 Test Procedure:

In ASTM G46, before any cleaning or destructive inspection, a visual inspection of the corroded metal surface was normally performed in its as-received state. By using a depth gauge or micrometre extent of the pitting was determined. The evaluation of the pitting was done with the help of Automated Profilometers.

Video 01: Crevice and pitting corrosion

ASTM G46 Test Specimen size:

For ASTM G46, the pit depth measurements are taken in the range of 0.04 mm to 0.34 mm.

Calculations:

Pitting probability can be calculated by using the following equation:

P = Np/N × 100

Np = Specimens that pit

N= total number of specimens

ASTM G46 Test Conclusion:

By using this ASTM G46 method, the pitting corrosion of a wide variety of metals is determined.