strip casting steel dierk raabe
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Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
1
Advances in the optimization of thin strip cast austenitic 304 stainless steel microstructures
D. Raabe1), R. Degenhardt2), R. Sellger2), B. Sander1), W. Klos2), M. Sachtleber2), L. Ernenputsch2)
1) Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany
2) ThyssenKrupp Nirosta GmbH, 47797 Krefeld, Germany
Max-Planck-Institut für Eisenforschung, ThyssenKruppMax-Planck-Institut für Eisenforschung, ThyssenKrupp
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
2
OverviewOverview
Introduction
Experimental
Strip casting microstructure
In-line forming strategies
Conclusions
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
3
Introduction and motivationIntroduction and motivation
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
4
Introduction and motivationIntroduction and motivation
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
5
Higher solidification rate
Higher and locally different heat flux
Much lower hot reduction
Properties of final product: cleaner, better corrosion resistance, weldable, good forming behaviour, lower anisotropy, good surface finish
New grades
Process specific features of strip cast (AISI 304) Process specific features of strip cast (AISI 304)
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
6
OverviewOverview
Introduction
Experimental
Strip casting microstructure
In-line forming strategies
Conclusions
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
7
3D electron – microscopy, 3D EBSD, texture3D electron – microscopy, 3D EBSD, texture
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
8
Principle of measurementPrinciple of measurementN
orm
al
Rolling
Texture, austentite Local misorientation (KAM1) phase content
Texture, ferrite and martensite IQ and interfacesLocal misorientation (KAM1)
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
9
Details from electron microscopyDetails from electron microscopyS
heer
nor
mal
Rolling
PhaseTexture ferrite and martensite
Delta
(round)
Martensite
(sharp)
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
10
Details from electron microscopyDetails from electron microscopy
Texture austentite Local misorientation (KAM1)
Martensite
(strong distorsion)
Martensite
(strong distorsion)
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
11
ThyssenKrupp Nirosta, Krefeld Strip Casting PlantThyssenKrupp Nirosta, Krefeld Strip Casting Plant
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
12
OverviewOverview
Introduction
Experimental
Strip casting microstructure
In-line forming strategies
Conclusions
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
13
304, 1.4301 Strip casting microstructure304, 1.4301 Strip casting microstructure
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
14
OverviewOverview
Introduction
Experimental
Strip casting microstructure
In-line forming strategies
Conclusions
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
15
Increase in equivalent strain and temperature
In-line formingIn-line formingN
orm
al
Rolling
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
16
In-line forming and final heat treatmentIn-line forming and final heat treatment
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
17
In-line forming and final heat treatmentIn-line forming and final heat treatment
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
18
Mechanical properties, deformation martensiteMechanical properties, deformation martensite
0,00
100
200
300
400
500
600
700
0,00 10 20 30 40 50 60 70 80
Strain [%]
Str
ess
[N/m
m²]
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
19
Mechanical properties, deformation martensiteMechanical properties, deformation martensitePhase discrimination+pattern quality+grain boundaries
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
20
Austenitic 304 stainless steels can be produced by thin strip casting, in-line hot rolling, and subsequent heat treatment with equivalent mechanical properties and even better microstructure homogeneity than steels produced by the conventional thick slab processing route.
The formation of deformation-induced α‘ martensite in austenitic stainless steels produced by the thin strip casting route is similar as in conventionally produced 304 steels.
Precise characterization of the different phases, interfaces, and crystallographic textures can be conducted by using a high resolution EBSD method.
ConclusionsConclusions
Prof. D. Raabe, lecture, 6th European Stainless Steel Conference, June 10-13 2008, Helsinki
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
21
references
• D. Raabe, M. Hölscher, F. Reher, K. Lücke: Scripta Metall. 29 (1993) 113116, Textures of strip cast Fe-16% Cr
• D. Raabe, M. Hölscher, M. Dubke, H. Pfeifer, H. Hanke, K. Lücke: Steel Research 4 (1993) 359363, Texture development of strip cast ferritic stainless steels
• D. Raabe, K. Lücke: Mater. Sc. Techn. 9 (1993) 302312, Textures of ferritic stainless steels
• D. Raabe: Metal. Mater. Trans. A 26A April (1995) 991998, Microstructure and crystallographic texture of strip cast and hot rolled austenitic stainless steel
• D. Raabe: Mater. Sc. Techn. 11 (1995) 461468, Textures of strip cast and hot rolled ferritic and austenitic stainless steel
• D. Raabe: Acta Mater. 45 (1997) 11371151, Texture and microstructure evolution during cold rolling of a strip cast and of a hot rolled austenitic stainless steel
• D. Raabe, R. Degenhardt, R. Sellger, W. Klos, M. Sachtleber, L. Ernenputsch: Steel Res. Int. 79 (2008) 440-444, Advances in the optimization of thin strip cast austenitic 304 stainless steel microstructures
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