The Influence of CoNiCrAlY Addition on the High Temperature Corrosion Behavior of CrSi₂ Alloy in an Air–Na₂SO₄–NaCl Gas Atmosphere

Abstract

In this study, an attempt has been made to improve the resistance of CrSi₂ alloy toward high temperature corrosion and promote the formation of a continuous and slow-growing SiO₂ scale on the alloy surface. For this purpose, spark plasma sintering was used to fabricate the CrSi₂ alloys containing various amounts of CoNiCrAlY. The sintered alloys were then corroded isothermally in an air–Na₂SO₄–NaCl gas atmosphere at three different temperatures of 923 and 1073 K for up to 720 ks and at 1273 K for 72 ks. XRD, SEM and SEM-EDS were utilized to examine the alloy structures and compositions before and after the high temperature corrosion test. The influence of CoNiCrAlY addition on the high temperature corrosion behavior of the CrSi₂ alloy was clarified.