Microstructure and damage processes in a nickel-based alloy exposed to molten glass

Abstract Nickel-based superalloys have already found many different applications in industrial facilities, especially those working at high temperatures, such as turbine blades in industrial and aircraft turbines, but also in the glass industry to construct glass shaping tools. During service, such tools are exposed to high temperature, high pressures and high-temperature corrosion in a severe corrosive medium like molten glass and thereby accentuate more exacting demands on high creep and corrosion resistance of nickel-based superalloys used in the glass industry. At present, the published data on microstructural changes and degradation processes in nickel-based superalloys used in the glass industry are sparse and often controversial. Therefore, the present study was initiated to perform a detailed evaluation of high temperature microstructural processes and damage in a carbide strengthened nickel-based superalloy which has been developed for an investment casting of spinner discs used in the glass industry for producing glass fibers. In this study, the relationship between the type, distribution and morphology of carbides, and the deformation and degradation processes in an alloy under investigation subjected to high temperature exposition was investigated. The paper aims to identify decisive factors governing high-temperature performance of the nickel-based superalloy under investigation.