The Influence of the Composition of Amorphous Alloys on Their Corrosion Resistance in Aggressive Environments of Different Nature

The influence of the elemental composition of strip amorphous alloys Fe_80.0Si_6.0B_14.0, Fe_78.5Ni_1.0Mo_0.5Si_6.0B_14.0; Fe_73.1Cu_1.0Nb_3.0Si_15.5B_7.4; Fe_51.7Ni_21.7Cr_6.2Mo_0.6V_1.5Si_5.2B_13.1 on corrosion resistance in 0.5 M aqueous solutions of NaCl, HCl, and KOH at T = (293 ± 1) K was investigated. The high corrosion resistance of Fe_51.7Ni_21.7Cr_6.2Mo_0.6V_1.5Si_5.2B_13.1 and Fe_73.1Cu_1.0Nb_3.0Si_15.5B_7.4 alloys in aggressive environments was established. Electrochemical parameters obtained both by the method of cyclic voltammetry and electrochemical impedance spectroscopy (EIS) indicate the formation of more durable surface layers in a 0.5 M potassium hydroxide aqueous solution on these alloys. The Cl^– ions (especially at low pH) under their long-term action are the more aggressive oxidizers of amorphous alloys compared to OH^– ions. During the passivation film formation in highly aggressive environments such alloy elements, which do not participate in this process, actively dissolve, and the main film-forming elements accumulate under the film, thus improving its protective properties.