International Standard Organization (ISO), 1998. 14p, 3651-2
This part of ISO 3651 specifies methods for the determination of the resistance to intergranular corrosion of ferritic, austenitic and ferritic-austenitic (duplex) stainless steels in media containing sulfuric acid. It also specifies the purposes which may be assigned to the test. The test methods included are:method A: the 16 % sulfuric acid/copper sulfate test (Monypenny Strauss test); method B: the 35 % sulfuric acid/copper sulfate test; method C: the 40 % sulfuric acid/ferric sulfate test. The methods are applicable to stainless steels supplied in the form of cast, rolled or forged products and tubes and intended for use in a mildly oxidizing acid medium (for example, sulfuric acid, phosphoric acid).Unless specified in the product standard, the method to be used, A, B or C, shall form the subject of an agreement between the interested parties.Annex A gives examples of application of the three methods on stainless steels.