Example of pitting after corrosion testing in accordance with ASTM G48 Method A . The test temperature of 22 °C is too aggressive for lean duplex grades such. Abstract ASTM G48 – “Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride. 1 These test methods are under the jurisdiction of ASTM Committee G01 on. Corrosion Results for ASTM G48 Standard Test Method for Pitting and Crevice.

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The sides only may be ground to a grit finish and the edges may be rounded. Zstm should ignore any edge corrosion If samples fail then they were not annealed correctly. Distinguish between pits on specimen edges and faces, recognizing that edge pits may affect pitting on specimen faces.

They use similar test solutions but they are done for very different reasons.

Testing by ASTM G48 for Pitting and Crevice Corrosion

This should indicate if you have any intermetallic phases present. Advanced search Show search help. Dear experts, The subjected testing was performed on Duplex steel for welding procedure qualification at testing temperature of 22C for suggested time period of 72 hours as per ASTM G48 using Method A.

The sharp edges of a specimen should be rounded to avoid cutting rubber bands or O-rings. Cover the container with a watch glass, transfer to a constant temperature bath, and allow to come to the equilibrium temperature of interest.

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Localized modes of 4g8 often result in occluded pits. The crevice former contact area of Method B is a The results may be used for ranking alloys in order of increasing resistance to pitting and crevice corrosion initiation under the specific conditions of these methods. Rinse the specimen in water and examine under the four points of contact for the O-rings or rubber bands and under both TFE-?


NOTE 7—Rubber bands or O-rings can be boiled in water prior to use to astj the removal of water-soluble ingredients that might affect corrosion. This is a simple immersion test where the test sample is placed in a temperature-controlled solution of FeCl 3.

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Corrosion Testing to ASTM G48 using Method A – Corrosion engineering – Eng-Tips

A more detailed examination will include the measurement of maximum pit depth, average pit depth, pit density, and crevice depth. All surfaces shall be exposed. We hired an independant 3rd party to perform corrosion testing to G48 Method A as per client requirements but by mistake 3rd party booked the specimen to A and testing was done also to A and result is OK.

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If the results for BM and consumables are satisfactory then only pursue 72 hrs test for weld coupons. If alloy consistently fails at the above specified testing regime, assuming that metallurgical factors are not contributors then the ways to get around it on GA test would be: Furthermore did asstm notice the presence of pits scattered on the entire surface of specimens or they are localized for example in the HAZ region?


Share on Tumblr Print. However, the G48 test is meant for ranking or qualification, and not as designed for determining a corrosion rate over time. It’s easy to join and it’s free. Red Flag This Post Please let us know here why this post is inappropriate. The latter test would, therefore, be considered more severe than the former. Yes, we did not ast HCL to the test solution.

Six procedures are described and identi?

Could any one explain the potential t48 for the failure and moreover what countermeasures shall be considered to avoid repeated failure? A and B are for qualification of alloys to pitting and crevice corrosion at specific temperatures, C g4 D are for determining the critical pitting and crevice corrosion temperatures of chromium and nickel alloys, and E and F are for stainless alloys.

C tests at that temperature is clear that the microstructure have been affected. NOTE 10—While asfm polished surface is preferred for uniformity, the test may be varied at the discretion of the investigator to evaluate other surface?

These include the cold? Measure the greatest depth of attack at the points of contact of the O-rings or rubber bands open notchand under the TFE-? See Notes 13 and 14 of Like what you saw?

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