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Application of a Continuous Annealing Process to the Production of Superplastic High-Carbon Steels

Published online by Cambridge University Press:  16 February 2011

K. Seto
Affiliation:
Kawasaki Steel Corp., Technical Research Div., Chiba, Japan
T. Kato
Affiliation:
Kawasaki Steel Corp., Technical Research Div., Chiba, Japan
H. Abe
Affiliation:
Kawasaki Steel Corp., Technical Research Div., Chiba, Japan
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Abstract

High-carbon steels with carbon content of more than 0.8wt% have been known to be superplastic by refining their microstructure. Many methods such as warm rolling have been proposed to refine the microstructure. But most of them are considered to be difficult to use as an actual production method. To make high-carbon steels superplastic and economical, application of a cold rolling and continuous annealing process has been examined.

Changes in microstructure of high-carbon hot rolled steels during the cold rolling and continuous annealing was investigated. By cold rolling with a reduction of more than 50%, a lamellar pearlite structure is deformed and heavily sheared, and a large strain energy is stored. Rapid annealing at temperatures just below the A1 temperature(1000K) is shown to spheroidize the sheared pearlite and to recrystallize the ferrite grains. After processing, the final structure consists of very fine cementite particles with 0.05–0.2μm diameter in a very fine equiaxed ferrite matrix with 0.1–0.5μm diameter. The processed steel shows total elongations of more than 700% and a strain rate sensitivity index of about 0.5 when deformed at 973K.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1. Sherby, O. D. and Wadsworth, J., in Deformation, Processing, and Structure, edited by Krauss, G. (1982 ASM Materials Science Seminar, 1984), pp. 355389.Google Scholar
2. Sherby, O. D., Walser, B., Young, C. M. and Cady, E. M., Scripta Metall. 9, 569(1975).Google Scholar
3. Walser, B. and Sherby, O. D., Metall. Trans. 10A, 1461(1979).Google Scholar
4. Langdon, T. G., Metall. Trans. 13A, 689(1982).Google Scholar
5. Furushiro, N., Toyoda, M. and Horn, S., Acta Metall. 36, 523(1988).Google Scholar
6. Hayden, H. W., Gibson, R. C., Merrick, H. F. and Brophy, J. H., Trans. Am. Soc. Metals 60, 3(1967).Google Scholar
7. Hayden, H. W., Floreen, S. and Goodell, P. D., Met. Trans. 3, 833(1972).Google Scholar