In-situ observation of sulfide precipitation in a low-carbon, titanium alloyed steel

Removal of inclusions is of greatsignificance to steelmakers and the scientific principles underpinning inclusion removal has been the subject of numerous investigations in the past and during the last few decades, it has become increasingly obvious that inclusions can be utilized as an effective tool for the control of microstructure1 . Manganese sulfide precipitates are known to crystallize and precipitate preferentially in interdendritic regions during solidification, due to segregation of manganese and sulphur2 and these inclusions have traditionally been used for the dual purpose of improving the machinability and controlling of grain structure in steel. Small MnS particles restrain grain growth in steel and Wakoh et al. 3 have shown that deoxidation practice can be used as a means to control the size and distribution of MnS. Moreover, microstructural control by manipulating the precipitation of sulfides has been used extensively to improve the toughness of microalloyed steels in general and specifically the toughness of heat-affected zones in welds3 .