OXYDISED ALUMINIUM PHASES IN STEELS
To determine soluble and insoluble aluminium in steel, chemists can choose between several techniques which have been presented and discussed. To give steelmakers correct results, the study of a reference method was undertaken during this research. After characterisation of the behaviour of synthetic oxides with regard to main dissolution reagents, the most selective mixture was chosen: this was a bromine + methanol mixture which can quantitatively separate soluble Al (metallic Al + Al of AlN) and insoluble Al (oxidised Al). Except for lime, all tested oxides were insoluble. The optimisation of the complete procedure using this reagent was done by analysing aluminium phases in different sets of steels. In some cases, the results obtained showed the limits of classical methods. With the procedure including Ca and Mg measurements, difficulties met in steel treated by complex deoxidation processes were explained and circumvented. With the reference method, preparation of homogeneous standards for soluble and insoluble Al was possible; these samples will be used to calibrate rapid methods such as optical emission spectrometry, electrolytic dissolution followed by colorimetry (RA 100 apparatus) or thermal decomposition of oxides giving data relative to oxygen phases. Finally, the economic impact of this research has been evaluated by considering future advantages for steelmakers, metallurgists and chemists.
Bibliographic Reference: EUR 12484 FR (1989) 67 PP., MF, ECU 4, BLOW-UP COPY ECU 8.75 THE OFFICE FOR OFFICIAL PUBLICATIONS OF THE EUROPEAN COMMUNITIES, L-2985 LUXEMBOURG
Record Number: 1989128044100 / Last updated on: 1992-08-10
Original language: FR