Investigation of the influence of the chemical composition of HSLA steel grades on the microstructure homogeneity during hot rolling in continuous rolling mills using a fast layer model

International Conference on Materials, Processing and Product Engineering 2015

Schmidtchen, M.^1 ; Rimnac, A.^2 ; Warczok, P.^3 ; Kozeschnik, E.^3,4 ; Bernhard, C.^5 ; Bragin, S.^2 ; Kawalla, R.^1 ; Linzer, B.^2

TU Bergakademie Freiberg, Institute of Metal Forming, Bemhard-v-Cotta-Str. 4, Freiberg

D-09599, Germany^1

Primetals Technologies Austria GmbH, MT CandR TI ESP, Linz, Austria^2

Institute of Materials Science and Technology, Vienna University of Technology, Getreidemarkt 9, Vienna

1060, Austria^3

Materials Center Leoben Forschung GmbH, Roseggerstraße 12, Leoben

8700, Austria^4

MU Leoben, Lehrstuhl für Eisen- und Stahlmetallurgie, Leoben

8700, Austria^5

关键词: Chemical compositions;    Continuous rolling mills;    Inhomogeneous materials;    Layer thickness distribution;    Micro-alloying elements;    Micro-structure evolutions;    Microstructure homogeneity;    Thin slab casting and direct rollings;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/119/1/012001/pdf
DOI  :  10.1088/1757-899X/119/1/012001

来源: IOP

【 摘 要 】

The newly developed LaySiMS simulation tool provides new insight for inhomogeneous material flow and microstructure evolution in an endless strip production (ESP) plant. A deepened understanding of the influence of inhomogeneities in initial material state, temperature profile and material flow and their impact on the finished product can be reached e.g. by allowing for variable layer thickness distributions in the roll gap. Coupling temperature, deformation work and work hardening/recrystallization phenomena accounts for covering important effects in the roll gap. The underlying concept of the LaySiMS approach will be outlined and new insight gained regarding microstructural evolution, shear and inhomogeneous stress and strain states in the roll gap as well as local residual stresses will be presented. For the case of thin slab casting and direct rolling (TSDR) the interrelation of inhomogeneous initial state, micro structure evolution and dissolution state of micro alloying elements within the roughing section of an ESP line will be discussed. Special emphasis is put on the influence of the local chemical composition arising from direct charging on throughthickness homogeneity of the final product. It is concluded that, due to the specific combination of large reductions in the high reduction mills (HRM) and the highly inhomogeneous inverse temperature profile, the ESP-concept provides great opportunities for homogenizing the microstructure across the strip thickness.