F. Inclusion Formation
The observation of inclusions in the FZs of low
alloyed steel welds is not new; in fact, extensive research
had been performed in the past to study the formation
mechanism of inclusions, their effects on subsequent
phase transformations, and the final mechanical properties
of the welds.[9–13] Recent work on the microstructural
evolution during welding of low-alloyed
automotive grade steel such as dual-phase (DP) steels
did not find any inclusion formation in the FZ.[14]
However, in TRIP steels, which exhibit superior
mechanical properties compared with many other
low-alloyed automotive grade steels, the presence of