An Iterative Algorithm to Determine Hot Strand Pressures during Continuous Casting of Round Blooms

Abstract:

Ovality defect of round bloom castings is the haunting defect of demanding grades steel, which can be attributed to excessive mechanical stress imposed by the roll containment especially at the unbending region. A 2-D elastic-plastic FEM model has been developed for the quantitative analysis of the effects of hot strand pressures on the ovality deformation and the contact normal force distribution. It is shown that higher friction force and smaller reduction deformation can be expected through the adoption of grooved rolls for given hot strand pressures as compared with plain rolls. For the determination of whether the given hot strand pressures can meet the requirement of strand downslide control in the caster, the resistances generated in the mold, secondary cooling zone and unbending zone are analyzed. Accordingly, an iterative algorithm has been presented to modify the hot strand pressures for given caster. A set of modified hot strand pressures has been computationally determined, which has been proved to be safe in production for casting round bloom with diameter up to Φ400mm with better roundness and less roller mark.

• Periodical: Advanced Materials Research (Volumes 284-286)
• Pages: 1196-1204
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.284-286.1196
• Online since: July 2011
• Authors: Ke Liu, Zhan Guang Han, Jia Quan Zhang
• Keywords: Hot Strand Pressure, Ovality Defect, Round Bloom Casting

References

[1] K. Okamura and H. Kawashima: ISIJ Int. Vol. 29(1989), p.666.

[2] A. Grill and K. Schwerdtfeger: Ironmaking Steelmaking Vol.6 (1979), p.131.

[3] M Deisinger and K. H. Tacke: Ironmaking Steelmaking Vol.24(1997), p.21.

[4] M. Uehara, I.V. Samarasekera and J.K. Brimacombe: Ironmaking Steelmaking Vol.13(1986),138-153.

[5] B.Barber, B.M. Leckenby and B.A. Lewis: Ironmaking Steelmaking Vol.18(1991), p.431.

[6] B. Barber and A. Perkins: Ironmaking and Steelmaking Vol.16 (1989): p.406.

[7] A. Grill, J. K. Brimacombe and F. Weiber: Ironmaking Steelmaking Vol.3(1976), p.38.

[8] H.Z. Han and J.Q. Zhang: Advanced Materials Research Vol.154-155(2011), p.171.

[9] H. Z. Qian, L. X. Cui and J. Q. Zhang: Chinese Specialty Steel Vol.2(2010), p.25. In Chinese.

[10] Man Yao, Wenhua Wang and Shuli Wei, etal: Journal of Dalian University of Technology Vol.42(2002), p.195. In Chinese.