| 11. |
- Alexis, Jonas, et al.
(författare)
-
Heating and electromagnetic stirring in a ladle furnace – a simulationmodel
- 2000
-
Ingår i: ISIJ International. - : Iron and Steel Institute of Japan. - 0915-1559 .- 1347-5460. ; 40:11, s. 1098-1104
-
Tidskriftsartikel (refereegranskat)abstract
- A three-dimensional simulation model coupling heating and induction stirring in an ASEA-SKF ladle furnace was developed. Data of the heat transfer from the area to the steel bath were predicted in a separate model and included as boundary conditions in a ladle model. The are model considers the contributions of heat transferred by of each of the following mechanisms: radiation, convection, condensation and energy transported by electrons. Predictions were made to simulate the change of temperature distribution in the ladle during simultaneous heating with electrodes and stirring by induction. A first attempt was made to compare the predictions with measured temperatures from a 100 t ASEA-SKF ladle. The agreement was found to be fairly good when heat-flux data for a 25 cm are length were used as input to the ladle model. This indicates that the model can be used for more in-depth studies of the effects of heating for ladles that are inductively stirred.
|
|
| 12. |
- Andersson, Joel, 1981-, et al.
(författare)
-
Hot Cracking of Allvac 718Plus, Alloy 718 and Waspaloy at Varestraint Testing
- 2008
-
Ingår i: 4th International Symposium on Aerospace Materials and Manufacturing Processes. - Montreal : Canadian Institute of Mining, Metallurgy and Petroleum. - 9781617386169 ; , s. 401-413, s. 401-413
-
Konferensbidrag (refereegranskat)abstract
- Varestraint testing together with DSC and SEM-EDX analyses have been performed as means of investigating the hot cracking susceptibility of Allvac 718Plus, alloy 718 and Waspaloy. The solidification sequences in Allvac 718Plus and alloy 718 were very similar to each other starting by an initial solidification of the gamma phase, gamma/MC reaction at around 1260°C and then finally ending the sequence by gamma/Laves eutectic reaction at around 1150°C. Waspaloy had the same solidification sequence, except no Laves phase formation takes place, and solidification started at a somewhat higher temperature as compared to alloy 718 and the solidification sequence ends by a gamma/MC reaction at around 1245°C. The total amount of hot cracking in Waspaloy was shown to be much less than that in alloy 718 and in Allvac 718Plus which is believed to be related to the presence of the Laves eutectic in the latter two alloys with corresponding larger solidification ranges. Hot cracking of 718Plus is slightly less than in 718.
|
|
| 13. |
- Andersson, Margareta A.T., et al.
(författare)
-
Slag-metal reactions during ladle treatment with focus on desulphurisation
- 2002
-
Ingår i: Ironmaking & steelmaking. - : Informa UK Limited. - 0301-9233 .- 1743-2812. ; 29:3, s. 224-232
-
Tidskriftsartikel (refereegranskat)abstract
- Within several cooperative projects, KTH (Royal Institute of Technology), Ovako Steel AB, and MEFOS have investigated the desulphurisation of bearing steel during vacuum degassing. The work includes thermodynamic calculations of the slag-metal equilibrium, CFD modelling of slag-metal reactions, and plant trials. Results from the various studies are presented and discussed in this paper. Models for predicting slag properties (sulphide capacity, viscosity, and oxide activities) in liquid slags as functions of slag composition and temperature have been used for the calculation of data which have been employed in static and dynamic modelling of sulphur refining. The results from static modelling show that the method allows fast and easy evaluation of the theoretical desulphurisation conditions during degassing at Ovako Steel AB, as well as theoretical determination of the parameters that have the greatest influence on the equilibrium sulphur distribution. The conclusion from dynamic modelling is that the vacuum degassing operation can be described dynamically with the present knowledge of sulphide capacity, sulphur distribution, viscosity, and oxide activities of ladle slags if this knowledge is combined with fluid flow modelling to derive the overall kinetics. The presented model approaches have been found useful in understanding the sulphur refining process at Ovako Steel AB. The dynamic modelling concept is also believed to have potential for dynamic descriptions of other slag-metal reactions in steelmaking.
|
|
| 14. |
- Azad, Abul Kalam, 1966, et al.
(författare)
-
Synthesis, structural and magnetic characterisation of the double perovskite A(2)MnMoO(6) (A = Ba, Sr)
- 2004
-
Ingår i: Journal of Alloys and Compounds. - 0925-8388. ; 364:1-2, s. 77-82
-
Tidskriftsartikel (refereegranskat)abstract
- A study of the crystallographic structure and magnetic properties of the double perovskites Ba2MnMoO6 and Sr2MnMoO6 in polycrystalline form has been carried out by means of neutron powder diffraction (NPD) and magnetization measurements. The Rietveld analysis of room temperature data shows that the Mn2+ and Mo6+ ions are B-site ordered, i.e. the structure is a NaCl-type ordered double perovskite. Ba2MnMoO6 crystallizes in the cubic space group Full-size image (<1 K) (a=8.1680(1)) and Sr2MnMoO6 crystallizes in the space group P42/n (a=7.9575(5), c=7.9583(9)). Bond valence sum (BVS) calculation revealed that these compounds have the valency pair of {Mn2+(3d5;t32ge2g), Mo6+(4d0)}. The magnetic measurements suggest that these compounds transform to an antiferromagnetic state below 10 K.
|
|
| 15. |
- Eklund, Nicklas, et al.
(författare)
-
Operation at High Pellet Ratio and Without External Slag Formers – Trials in an Experimental Blast Furnace
- 2009
-
Ingår i: Steel Research International. - 1611-3683 .- 1869-344X. ; 80:6, s. 379-389, s. 379-384
-
Tidskriftsartikel (refereegranskat)abstract
- Blast furnaces that operate with pellets and sinter normally use high basicity sinter and acid pellets to balance the slag chemistry. When external additives are used, irregular slag formation occurs due to their uneven distribution in the burden. If basic sinter is used together with a large amount of acid pellets, all additives are incorporated in the iron bearing materials with an improved burden mixture as a consequence. During a campaign in the LKAB Experimental Blast Furnace, pellets and sinter were operated at an ultra low slag volume. A high amount of pellets was balanced with high basicity sinter. An improved blast furnace operation is shown when operating at ultra low slag volume and without external slag formers. During the test period, the blast furnace operation was smooth and stable, and the reductant rate was decreased.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
|
|
