The specimens were prepared using Cr2O3 micropowder, TiO2 micropowder and chromium powder as starting materials, PVA as binder, after spraying granulation and cold isostatic pressing, firing at 1 450 ℃ for 3 h in sta...The specimens were prepared using Cr2O3 micropowder, TiO2 micropowder and chromium powder as starting materials, PVA as binder, after spraying granulation and cold isostatic pressing, firing at 1 450 ℃ for 3 h in standard nitrogen and oxygen control atmosphere （ oxygen partial pressure was 1 010 Pa and 10. 1 Pa, respectively）. Effects of chromium powder （ mass percent were 0, 0. 5% , 1.0% , 1.5% and 2.0% , respectively） on sintering behaviors of Cr2O3 materials were researched. The results show that： adding 0. 5% chromium powder can obviously decrease the oxygen partial pressure in the specimens. Meanwhile, because the expansion caused by the oxidation reaction is small, Cr2O3 materials could realize the densifieation sintering under 1 010 Pa and 10. 1 Pa of oxygen partial pressure. The chromium powder addition in Cr2O3 materials shouldn＇t be excessive, otherwise, the expansion reaction occupies a dominant position, which deteriorates the properties of the materials.展开更多
Six kinds of Cr2O3 - Al2 O3 fused grains （the mass percent of Cr203 was 15%, 40%, 50%, 60%, 85% and 99%, respectively ） were prepared using chrome green and Al203 powder as starting materials by electro-fnsion, n...Six kinds of Cr2O3 - Al2 O3 fused grains （the mass percent of Cr203 was 15%, 40%, 50%, 60%, 85% and 99%, respectively ） were prepared using chrome green and Al203 powder as starting materials by electro-fnsion, named as CR15, CR40, CR50, CR60, CR85, and CR99, respectively. The corrosion resistance of the six kinds of Cr2O3- Al2O3.fused grains （4-1 ram） was studied using rotary slag corrosion method. The results show that： （ 1 ） the corrosion resistance of the fused grains increases with the Cr203 content and the grain size increasing; （2）the grains of CR99 and CR85 with higher Cr2O3 content are corroded at the slag surJace layer, because FeO and Al2O3. in the slag corrode the grains ; FeO reacts with Cr2O3 in the aggregates.forming （Fe, Cr ）3O4 ,spinel firstly, and the spinel reacts with other phases forming composite spinel; when FeO is fidly consumed, Al2 O3 penetrated into the grains reacts with Cr2O3 Jorming Al2O3 - Cr2O3 solid solution on the grains surface; （3） for CR60, the corrosion exists both in the slag surface layer and in the penetration layer; in the penetration layer, CaO and SiO2 react with Al2O3 in Al2O3 - Cr2O3 solid solution forming anorthite , gehlenite ,and glass phase; the grains of CR50, CR40 and CRI5 have the same corrosion mechanism with CR60 in the penetration layer.展开更多
文摘The specimens were prepared using Cr2O3 micropowder, TiO2 micropowder and chromium powder as starting materials, PVA as binder, after spraying granulation and cold isostatic pressing, firing at 1 450 ℃ for 3 h in standard nitrogen and oxygen control atmosphere （ oxygen partial pressure was 1 010 Pa and 10. 1 Pa, respectively）. Effects of chromium powder （ mass percent were 0, 0. 5% , 1.0% , 1.5% and 2.0% , respectively） on sintering behaviors of Cr2O3 materials were researched. The results show that： adding 0. 5% chromium powder can obviously decrease the oxygen partial pressure in the specimens. Meanwhile, because the expansion caused by the oxidation reaction is small, Cr2O3 materials could realize the densifieation sintering under 1 010 Pa and 10. 1 Pa of oxygen partial pressure. The chromium powder addition in Cr2O3 materials shouldn＇t be excessive, otherwise, the expansion reaction occupies a dominant position, which deteriorates the properties of the materials.
文摘Six kinds of Cr2O3 - Al2 O3 fused grains （the mass percent of Cr203 was 15%, 40%, 50%, 60%, 85% and 99%, respectively ） were prepared using chrome green and Al203 powder as starting materials by electro-fnsion, named as CR15, CR40, CR50, CR60, CR85, and CR99, respectively. The corrosion resistance of the six kinds of Cr2O3- Al2O3.fused grains （4-1 ram） was studied using rotary slag corrosion method. The results show that： （ 1 ） the corrosion resistance of the fused grains increases with the Cr203 content and the grain size increasing; （2）the grains of CR99 and CR85 with higher Cr2O3 content are corroded at the slag surJace layer, because FeO and Al2O3. in the slag corrode the grains ; FeO reacts with Cr2O3 in the aggregates.forming （Fe, Cr ）3O4 ,spinel firstly, and the spinel reacts with other phases forming composite spinel; when FeO is fidly consumed, Al2 O3 penetrated into the grains reacts with Cr2O3 Jorming Al2O3 - Cr2O3 solid solution on the grains surface; （3） for CR60, the corrosion exists both in the slag surface layer and in the penetration layer; in the penetration layer, CaO and SiO2 react with Al2O3 in Al2O3 - Cr2O3 solid solution forming anorthite , gehlenite ,and glass phase; the grains of CR50, CR40 and CRI5 have the same corrosion mechanism with CR60 in the penetration layer.
