Study on Formation Mechanism of Frame-Shaped Segregation in 40Cr Wire Rod Rolled from Bloom

Abstract:

This paper has studied the formation mechanism of frame-shaped segregation in 40Cr wire rod rolled from bloom by means of the composition measurement, the electron microscopic observation and the energy spectrum analysis method. The results show that the frame-shaped segregation in wire rod originated from the positive segregation in columnar-to-equiaxed grain transition zone of bloom. The main influence factors are the solidification behavior of liquid steel in columnar-to-equiaxed grain transition zone, the temperature gradient of different solidification regions in bloom, the diffusion rate of the solute and inclusions in transition zone and so on. It may reduce the frame-shaped segregation by improving the purity of liquid steel, adopting the electromagnetic stirring in secondary cooling zone and enhancing the cooling intensity of the secondary cooling zone.

• Periodical: Advanced Materials Research (Volume 402)
• Pages: 211-214
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.402.211
• Online since: November 2011
• Authors: Chang Gui Cheng, Zhong Tian Liu, Wen Cheng Wan, Yong Rui Zheng, Yong Tian Di
• Keywords: 40Cr, Bloom, Formation Mechanism, Frame-Shaped Segregation, Wire Rod

References

[1] A. Scholes: Ironmaking and Steelmaking Vol. 32(2005), p.101

[2] G. Lesoult: Materials Science and Engineering A Vol. 413(2005), p.19

[3] G. Krauss: Metallurgical and Materials Transactions B Vol. 34B(2003), p.781

[4] J.P. GU and C. BECKERMANN: Metallurgical and Materials Transactions A Vol. 30A(1999), p.1357

[5] M. Suzuki, K. Kimura, A. Kawami and et al: 1989 steelmaking conference proceedings. (1989), p.115

[6] C. G. Cheng, F. Che, J. Shuai et al: Continuous Casting Vol. 20(2009), p.39. (in Chinese)

[7] P. Zhao: Alloy Steel smelting (Metallurgical Industry Press, Beijing, 1992). p.19. (in Chinese)