To compare the performance of HAYNES® 625 alloy with that of other materials, it is useful to plot the 0.1 mm/y lines. In the following graphs, the lines for 625 alloy are compared with those of G-35 alloy, 254SMO alloy, and 316L stainless steel, in hydrochloric and sulfuric acids. The hydrochloric acid concentration limit of 20% is the azeotrope, above which corrosion tests are less reliable.