On the method of evaluation of phase selectivity during anodic dissolution of heterogeneous alloys

The technique is described for a quantitative evaluation of selective dissolution of a heterogeneous alloy with the use of a phase chemical analysis and analysis of the electrolyte after potentiostatic exposures. Anodic dissolution has been studied in 20% H3PO4 of an age-hardened alloy EhP 724 with the composition: C, 0.07; W, 17.6; Mo, 3.18; Co, 16.4; Cr, 4.1; V, 1.14; Ni, 2.26; Fe, 54.0. The proposed technique allows for evaluating the phase selectivity upon anodic dissolution of heterogeneous alloys and, in a number of cases, selectivity of dissolution of the separate elements within the phases