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High silicon steels (Fe-6.5wt%Si) are excellent soft magnetic materials due to their high electrical resistivity and very low magnetostriction. However, as the Si content is increased above 3.5wt% the alloys become too brittle to be hot/cold rolled, therefore limiting processing possibilities. It has been verified that the B2 long-range ordering is the main cause for material britlleness since it induces the formation of dissociated superlattice dislocations and the correlated high stress concentrations leading to premature fracture. The combination of Al addition and high solidification rates may changes the kinetic of these ordering reaction. In this work in-situ X-ray diffraction from a high-energy syncrotron radiation source was employed in order to study disorder/order reaction (A2→ B2 + DO 3 ) in spray formed Fe-6.5wt%Si and Fe-5wt%Si-1.5wt%Al alloys at 350ºC, 770ºC and 798ºC. It may be predict that the ordering reaction from A2 (disordered bcc) to B2 is suppressed above about 800ºC in the Fe-6.5wt%Si alloy, but not below 600ºC, where A2 transforms to B2 + DO 3 . The results of the present work showed that the addition of aluminium coupled with the solidification rates prevailing during spray forming processing avoid the B2 ordering reaction even at 350ºC, but did not avoid the formation of DO 3 for both alloys in all temperatures studied.