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A Study of Slag-Steel-Inclusion Interaction
三年级作文辅导
During Ladle Treatment
Johan Björklund
Licentiate Thesis
School of Industrial Engineering and Management
Division of Applied Process Metallurgy
gzip是什么Royal Institute of Technology
SE-100 44 Stockholm
Sweden
Akademisk avhandling som med tillstånd av Kungliga Tekniska Högskolan i
小学考试成绩查询Stockholm, framlägges för offentlig granskning för avläggande av Teknologie licentiatexamen, torsdagen den 15 Juni 2006, kl. 10.00 i sal B2, Brinellvägen 23,
Kungliga Tekniska Högskolan, Stockholm
I SRN KTH/MSE--06/46--SE+APRMETU/AVH
ISBN 91-7178-403-9vactomy
Johan Björklund. A Study of Slag-Steel-Inclusion Interaction During Ladle Treatment KTH School of Industrial Engineering and Management
Division of Applied Process Metallurgy
Royal Institute of Technology
SE-100 44 Stockholm
英语外教Sweden
I SRN KTH/MSE--06/46--SE+APRMETU/AVH
ISBN 91-7178-403-9
© The Author
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A BSTRACT
The thesis is bad on two supplements with two major objectives. In the first supplement equilibrium top slag-steel bulk and inclusions-steel bulk were investigated by comparison between calculated and measured oxygen activity values. This was done by applying different oxide activity models for slags combined with thermodynamic calculations. In the cond supplement the inclusion composition is studied during the ladle refining process. The inclusion composition is related to top slag composition and other parameters during ladle treatment.
The work was carried out by collecting data during well controlled sampling procedures at two different steel plants. Extensive inclusion analys in Scanning Electron Microscope, SEM, were done. The data was ud together with thermodynamics for a description of the interaction between slag-steel-inclusion interaction during ladle treatment.
Evaluation of inclusion composition during the ladle refining have revealed that the majority of the inclusions belonged to the system Al2O3-CaO-MgO-SiO2 and showed a continuous composition change throughout the ladle refining process, from high Al2O3, via MgO-spinel to finally complex types rich in CaO and Al2O3. The final composition after vacuum treatment was found to be clo to the top slag composition. Small process parameter changes and practical variations during ladle refining were proven to give large differences of the inclusion composition. Finally, it was concluded
that equilibrium does not exist between top slag and steel bulk, with respect to oxygen, for the studied conditions. However, the equilibrium does exist between the steel bulk and inclusion.
Keywords: Ladle treatment, steel, slag, inclusions, ladle, refining, vacuum, tool steel, oxide activity, slag models, oxygen, equilibrium
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A CKNOWLEDGMENTS
14岁英语学习I am very grateful to my supervisor Doctor Margareta Andersson, for help throughout the whole project with constructive criticism and ideas as well as theoretical concerns during this project.
I would also like to express my sincere gratitude and appreciation to my supervisor Professor Pär Jönsson for his guidance and constant encouragement during the work of this licentiate thesis.
国家注册审核员考试The author would also like to thank the rest of the colleagues and friends at the Department of Materials Science and Engineering.
All the thanks to Ovako Steel AB and Uddeholm Tooling AB for making this work possible and the hospitality during the periods of trial. Special thanks to Patrik Undvall, Anders Lind and Garry Wicks at Ovako Steel AB and Karin Steneholm, Mlly Nsotta and Alf Sandberg at Uddeholm Tooling. At the same time I wish to thank Birger Wahlberg from MEFOS for support during the trials at Ovako Steel AB.
Financial support from STEM and Jernkontoret, as well as grants for writing this thesis from A H Göranssons and Gerhard von Hofstens foundation are greatly acknowledged.
And finally, I would like to thank all my friends and family for the encouragement to keep me on working, even though they had no clue about what I have really been working with.
Johan Björklundalimi
Stockholm, May 2006
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