Influence of treatments using different magnesium ferroalloys on the melt quality and the solidification processes of ductile of ductile irons

In this work the metallurgical consequences of treatments applied on ductile irons using ferroalloys with differentmagnesium contents are analysed. The solidification processes have an important influence on the mechanicalproperties and the functionality of the iron castings along their service period. Consequently, the comparison ofthe characteristics of the cooling curves recorded from the melt and the active oxygen and sulphur contents havebeen used for quantifying the effects of treatments performed utilizing different types of commercial FeSiMg. Theaddition of magnesium into the melt strongly removes sulphur and oxygen contents and important degradations ofthe metallurgical quality are finally obtained as a consequence of them. On the other hand, the composition of theresulting slags and the evolution of the melt characteristics as a function of the remaining time into the pouringdevice is investigated. The magnesium content in ferroalloys becomes a critical parameter in the evolution of themelt quality of treated irons.