Is “modified G 48” testing the same thing as A 923 Method C?
ASTM G 48 Practice A and A 923 Method C are similar to the extent that they use similar equipment and laboratory procedures. However, they are substantially different in their application. ASTM G 48 is a description of laboratory procedure, but it does not specify the temperature of testing, the time of exposure, the technique of assessing corrosion, and an acceptance criterion. The “modified G 48” test indicated that the individual ordering specification was attempting to address these deficiencies, but few specifications addressed all of them. ASTM A 923 Method C specifically addresses each of these issues, and provides a basis for acceptance of the duplex stainless steels with regard to the absence of detrimental intermetallic phases. One important difference is that G 48 permits the tester to disregard corrosion on the edges of the specimen. This permission is totally inappropriate for use of the test to demonstrate the absence of intermetallic phases in duplex stainless steels. It
