Catalytic hydrodeoxygenation (HDO) presents a promising method to improve the quality of crude pyrolysis oil. The upgraded oils have untapped potential to replace fossil fuels partially or completely. In our previous study, corrosion of UNS S30400 was investigated at temperature range from 80-325 °C during catalytic HDO of pyrolysis oil by supercritical ethanol with in-situ hydrogen source. It was found that there was few corrosion damage in this system on UNS S30400. In this study, alloy UNS S50200 was investigated in same reaction system at reaction temperature range from 80-375 °C to facilitate the commercialization of the developed HDO technology by finding a more economic reactor material. After 20 h exposure, weight change and weight loss measurements were used to evaluate the corrosion rate of alloy UNS S50200. And modern microcopy techniques including SEM, EDS, XRD were utilized for corrosion products analysis.