Metallographic characterization of the heat affected zone in welded joints with multiple defects

Abstract

This paper is based on extensive research about the influence of multiple different welded joint defects on the integrity of welded structures. In this particular case, the focus was on the heat affected zone and its different sub regions - up to this point, it was observed as a whole, with homogeneous mechanical properties along its cross-section. Due to the need to describe its behaviour in more detail, it was concluded that metallographic characterisation of the heat affected zone is necessary. Metallographic tests have provided a detailed insight into the micro-structures with the heat affected zone, which would be difficult to predict in this case, due to specific conditions, i.e., a welding technology which was adopted with the purpose of deliberately causing a number of defects in the welded joint. This would result in a more realistic distribution of mechanical properties along the heat affected zone, which in turn would provide more accurate input data for numerical simulations, since the use of finite element method will be the next step in this research.