Stabilisation and Microstructural Modification of Stainless Steel Converter Slag by Addition of an Alumina Rich By-Product

Content Provider	Semantic Scholar
Author	Iacobescu, Remus Ion Malfliet, Annelies Machiels, Lieven Jones, Peter Tom Blanpain, Bart Pontikes, Yiannis
Copyright Year	2014
Abstract	This work aimed to assess the possibility of stabilising argon oxygen decarburisation (AOD) stainless steel slag with CaO/SiO2 ~ 1.6, by using a secondary alumina by-product (~75 wt% Al2O3, referred herein as SA, found under the name “Valoxy®”) and reduced levels of B2O3. Two groups of samples were synthesised: one reference group with AOD slag and 0.26, 0.16, 0.10 and 0.05 wt% of B2O3 and one with equivalent compositions but to which 5 wt% of SA is added. Experimentally, the slags were produced in a platinum crucible in a resistance furnace, heated with 5 °C/min until 1,640 °C, equilibrated for 1 h, followed by slow cooling to room temperature. The mineralogical composition was analysed by QXRD whereas the micro-hardness was measured through a Vickers indentation test. The microchemistry and morphology were analysed by EPMA–WDS. Analysis indicated that AOD was successfully stabilised by 5 wt% SA and 0.10 wt% B2O3, whereas for 0.05 wt% B2O3, volumetric expansion occurred over time. In terms of mineralogy, the use of SA promoted the formation of spinel instead of gehlenite. Electron microscopy revealed a more dense morphology in the samples with SA when compared to the reference ones. Elemental maps indicated that Cr predominantly participates in the spinel phase. Vickers tests showed a slight increase in hardness in the samples with SA. In conclusion, the addition of SA resulted in substantially different microstructures that appear to be promising in terms of chemical and mechanical stability. However, in terms of volumes the required addition levels for effective stabilisation are substantial compared to B2O3 additions.
Starting Page	343
Ending Page	353
Page Count	11
File Format	PDF HTM / HTML
DOI	10.1007/s12649-013-9287-y
Volume Number	5
Alternate Webpage(s)	https://core.ac.uk/download/pdf/34588471.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article