ISO 21610:2009 specifies accelerated methods for the determination of the intergranular corrosion susceptibility of austenitic stainless steels. The methods specified by the standard provide results identical to those obtained when using ISO 3651‑1 and ISO 3651‑2, but the test period for the accelerated corrosion test is shorter.

The standard is applicable to the testing of various kinds of metal production, including two-layer rolled metal, welded joints, deposited metal and weld seam metal.

Two test methods are specified:

• method A: corrosion test in a solution of copper sulfate and concentrated sulfuric acid in the presence of metallic copper;
• method B: corrosion test in a solution of copper sulfate, sulfuric acid and copper fluoride in the presence of metallic copper.