Corrosion Behaviors of Fe-Based Shape-Memory Alloys

摘要

Fe-30Mn-6Si, Fe-30Mn-6Si-5Cr and Fe-13Mn-5Si-12Cr-5Ni shape memory alloys were prepared by vacuum induction melting. Chemical-immersion and electrochemical potentiodynamic tests were conducted to investigate the corrosion behaviors of these alloys. Experimental results show that in 3.5% NaCl solution, the Fe-l3Mn-5Si-12Cr-5Ni alloy had the best chemical corrosion resistance, whereas the Fe-30Mn-6Si-5Cr alloy was locally attacked, forming many corrosion pits after immersion test. In addition, the detachment of the corrosion product covering the Fe-30Mn-6Si alloy caused an abrupt increase in the weight loss. After 2 h of heat treatment at 1000℃, the corrosion potential of the Fe-30Mn-6Si alloy increased due to the formation of α -ferrite, while the Fe-30Mn-6Si-5Cr alloy became more active.