The Corrosion Behavior of Ni3Al/Ni3V Two-Phase Intermetallic Compounds in Various Acidic Solutions

[摘要] The corrosion behavior of the Ni3Al/Ni3V two-phase intermetallic compounds with and without minor elements (Nb, Co, and Cr) to be composed of L12phase (Ni3Al) and a mixed phase of L12(Ni3Al) and D022(Ni3V) has been investigated by using an immersion test in 0.5 kmol/m3HCl, H2SO4, and HNO3solutions. The surface morphology was observed before and after the immersion test by scanning electron microscope (SEM). The results were compared to those of the L12single-phase Ni3(Si,Ti) and austenitic stainless steel type 304. In all acidic solutions, preferential dissolution of (L12+D022) phase was found in Ni3Al/Ni3V, but no intergranular attack, whereas the attacks took place on Ni3(Si,Ti). The Ni3Al/Ni3V showed a higher corrosion resistance in HCl solution and a lower resistance in HNO3solution than Ni3(Si,Ti) and type 304. The addition of the minor elements enhanced corrosion resistance in HNO3solution, but not clearly in HCl and H2SO4solutions. In HCl and H2SO4, their weight losses during the immersion test were almost the same.

[学科分类] 材料工程