Elimination of Dissolved Nitrogen in Iron by Aluminium

The elimination of nitrogen by aluminium from molten iron was studied by determining the contents of AlN nitrogen and dissolved atomic nitrogen separately with respects to molten Fe-Al alloys which sufficiently reacted with nitrogen gas at one atmosphere. There was no clear relation between the content of AlN nitrogen and that of aluminium in the sample, but dissolved nitrogen decreased at first and then increased gradually as the content of aluminium increased with a minimum nitrogen content at about 1∼4 wt. per cent aluminium. Such a relation was clarified from the view point of statistical thermodynamics.When pure molten aluminium reacted with nitrogen gas at one atmosphere, AlN was formed and nitrogen did not dissolve in the quasilattice of molten aluminium as atomic solutes.