MYRRHA is short ‘Multi-purpose hYbrid Research Reactor for High-tech Applications’ which is an first of its kind accelerator driven system currently developed at SCK•CEN. Being one of the largest research project in Belgium it will allow material developments for fusion reactors, material developments for GEN IV systems, fuel developments for innovative reactor systems and radioisotope production for medical and industrial applications. The selected primary coolant for the reactor part and at the same time also spallation target is liquid lead bismuth eutectic (LBE) which has significant safety benefits. Nevertheless, when building a new system it is essential to investigate its potential effects on structural and functional materials. Among these effects liquid metal corrosion is one of the most important topics in the MYRRHA materials research and qualification program. So far different correlations to estimate the corrosion effects on steels have been developed in the recent years and are continuously updated. Nevertheless, long term data is not yet available. Therefore, targeted exposure experiments were started several years ago and are expected to reach 18000 hours of accumulated exposure time in 2019. Within this PhD topic these (world) unique sets of samples should be thoroughly investigated towards microstructural changes and corrosion mechanisms. In order to perform the necessary investigations the student will learn to independently operate high end microscopy techniques such as scanning and transmission electron microscopy, EBSD, and FIB as well as interpretation of the gained results. While scientifically challenging the results will also have direct practical application within the materials selection and licensing process of MYRRHA.