High Temperature Corrosion Behavior of Si-Containing Alloys in the Liquid Phase of Na2SO4 25.7 Mass% NaCl
The high temperature corrosion behavior of Si-containing alloys consisting of Cr-Si-Ni and CoNiCrAlY-Si alloys fabricated by spark plasma sintering technique was investigated in the liquid phase of Na2SO4 + 25.7 mass% NaCl at temperatures ranging from 923-1273 K. The purpose of this study is to develop excellent corrosion resistant alloys for coating applications. Our experimental results show the CrSi2 alloy with 10 mass% Ni content and the CoNiCrAlY alloy with 30 mass% Si content are the most promising materials for applications in this atmosphere. This is due to the formation of a protective SiO2 and Al2O3/SiO2 scale, respectively. The formation of a dense and continuous oxide layer composed and/or consisted of SiO2 plays a significant role in hindering the inward diffusion of chlorine and sulfur to the alloys substrate. Particularly, the corrosion mechanism of Cr-Si-Ni alloys and the influence of Ni addition on the corrosion resistance of CrSi2 alloy are discussed in the present paper.
I. Bezverkhyy, S. Chevalier and O. Politano
T. Sudiro et al., "High Temperature Corrosion Behavior of Si-Containing Alloys in the Liquid Phase of Na2SO4 25.7 Mass% NaCl", Defect and Diffusion Forum, Vols. 323-325, pp. 353-358, 2012