Optimization of the microstructure and corrosion resistance of Finemet type alloys in KOH solutions

The effect of Cr replacement for Fe on the kinetics of Cu clustering and on the electrochemical behavior of Fe73.5−XCu1Nb3Si13.5B9CrX amorphous alloys has been studied for improving the corrosion resistance of Fe–Si–B–Nb–Cu Finemet type alloys. The corrosion testing of these materials was performed in 0.5 M KOH solutions using AC impedance measurements. These experimental results are discussed from the thermodynamical point of view, and the optimized microstructure to achieve a high corrosion resistance has been found.