Influence of Cooling Rate and Steel Composition on the Scale Failure Characteristics during Cooling of Si-Containing Low Carbon Steels

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Abstract:

The scale failure temperature (Tf) during cooling from 1173 K of low carbon steels containing Si of up to 2.1% was assessed by in-situ acoustic emission measurements and analyses including wavelet transform. In general, Tf lowers with an increase in the Si content for steels without S or P, indicating that the scales on higher Si-content steels are more resistant to thermal stress. This tendency becomes larger for higher cooling rate. Contrarily, Tf rises with an increase in the S, P or (S+P) content for 1% Si steels. This means that the scale failure is enhanced by the additives. S segregates at the scale/substrate interface and seems to enhance the partial scale separation. P is incorporated in the (FeO+SiO2) layer on the substrate and forms microspores at the interface to the FeO layer, and thus enhanced the crack initiation by providing the sites for stress concentration. Wavelet transform showed that the scale failure mode is mainly the following; local separation of the scale over a small area takes place first, and then cracking in the scale follows. For steels containing S or/and P scale cracking is the initial failure in many cases, probably because the stress concentration sites are already formed during the scale growth.

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Materials Science Forum (Volumes 522-523)

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505-512

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August 2006

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© 2006 Trans Tech Publications Ltd. All Rights Reserved

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[1] T. Fukagawa, H. Okada and Y. Maehara: ISIJ Inter. Vol. 34 (1994), p.906.

Google Scholar

[2] B. Gleeson, S. M. M. Hadavi and D. J. Young: Mater. High-Temperatures Vol. 17, (2000), p.311.

Google Scholar

[3] R. Y. Chen and W. Y. D. Yuen: Oxid. Met. Vol. 56 (2001), p.89.

Google Scholar

[4] Y. Hanamoto: M. Sc. Thesis, Osaka Univ., (2005) (in Japanese).

Google Scholar

[5] Q. -Q. Ni and M. Iwamoto: Engineering Fracture Mechanics Vol. 69 (2002), p.717.

Google Scholar

[6] M. Schutze: Oxid. Met. Vol. 44 (1995), p.29.

Google Scholar

[7] D. L. Deadmore and C. E. Lowell: Oxid. Met. Vol. 11 (1977), p.91.

Google Scholar

[8] H. E. Evans: Materials Science and Technology, Vol. 4 (1988), p.415.

Google Scholar

[9] P. Y. Hou and J. Stringer: Oxid. Met. Vol. 38 (1992), p.323.

Google Scholar

[10] D. G. Lees: Oxid. Met. Vol. 27 (1987), p.75.

Google Scholar

[11] S. Taniguchi, K. Yamamoto, D. Megumi and T. Shibata: Mater. Sci. Eng. Vol. A308 (2001), p.250.

Google Scholar