Influence of Chlorides on High-Temperature Corrosion of Heat-Resistant Nickel Alloy VZh718

VZh718 alloy, an analogue of the foreign heat-resistant alloy Inconel IN718, was tested for its tendency to corrosion in NaCl, Na2SO4 + NaCl, Na2SO4 + K2SO4 environments at temperatures of 700 and 850°C. It was found that in the absence of chlorides, VZh718 alloy has a high resistance to hot corrosion. The determining role of chlorides in the mechanism of high-temperature corrosion of VZh718 alloy is shown. The presence of sulfates, depending on the temperature, can lead to both a slowdown in chloride-induced corrosion processes and, conversely, significantly accelerate them.