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Sulfide Stability, Void Nucleation and the Toughness of Ultra High Strength Steels

Published online by Cambridge University Press:  28 February 2011

W. M. Garrison Jr.
Affiliation:
Department of Metallurgical Engineering and Materials ScienceCarnegie Mellon UniversityPittsburgh, PA 15213
J. L. Maloney
Affiliation:
Department of Metallurgical Engineering and Materials ScienceCarnegie Mellon UniversityPittsburgh, PA 15213
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Abstract

The upper shelf fracture toughness of ultra high strength steels is dependent on both the microstructure, which is determined by composition and heat treatment, and on the inclusions present in the steel. The inclusions In ultra high strength steels are typically oxides and sulfides [1]. In most ultra high strength steels the sulfides are manganese sulfides, although depending on the composition of the steel and the melt practice used, other sulfides are found, such as chromium sulfide, calcium sulfide and lanthanum oxy-sulfide [2]. If the inclusions can be regarded as pre-existing voids then the inclusion volume fraction and spacing appear to be sufficient to characterize the inclusion population from the standpoint of fracture toughness [3,4]. The purpose of this paper is to discuss results which show sulfur can be gettered as particles which are much more resistant to void nucleation than manganese sulfides and that this increased resistance to void nucleation can result in vastly improved upper shelf fracture toughness. In particular, when HY180 steel contains manganese sulfides the fracture toughness is about 250 MPa but when the sulfur is gettered as particles containing titanium, carbon and sulfur the fracture toughness of HY180 steel will approach 550 MPa . These particles, believed to be titanium carbosulfides, are much more resistant to void nucleation than manganese sulfides and this increased resistance to void nucleation appears to be the reason for the improved fracture toughness.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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References

1. Pickering, F.B., “The Constitution of Non-metallic Inclusions in Steel”, Proceedings of Conference on Inclusions and Their Effects on Steel Properties, University of Leeds, 17-19 September 1974, British Steel Corporation.Google Scholar
2. Kiessling, R. and Lange, N., Non-metallic Inclusions in Steel, 2nd ed. (The Metals Society, London, 1978).Google Scholar
3. Rice, J.R. and Johnson, M.A., in Inelastic Behavior of Solids, edited by Kanninen, M.F., Adler, W.G., Rosenfield, A.R. and Jaffee, R.I., (McGraw-Hill, New York, 1970), p. 641.Google Scholar
4. Green, G. and Knott, J.F., J. Engineering. Materials Technology, Trans. ASME 98, 37 (1976).Google Scholar
5. Speich, G.R. Jr., Dabkowski, D.S. and Porter, L.F., Metallurgical Transactions 4, 303 (1973).Google Scholar
6. Bray, J.W., Maloney, J.L., Raghavan, K.S. and Garrison, W.M. Jr., “A Comparison of the Fracture Behavior of Two Commercially Produced Heats of HY180 Steel Differing in Sulfide Type”, Metallurgical Transactions A, in press.Google Scholar
7. Meyer, L., Heisterkamp, F. and Lauterborn, D., in “Processing and Properties of Low Carbon Steel”, edited by Gray, J. M., (The Metallurgical Society of AIME, Warrendale, PA, 1973), p. 297.Google Scholar
8. Ball, C.J., Metal Science 18, 577 (1984).Google Scholar
9. Casa, C. da and Nileshwar, V.B., Journal of Iron and Steel Institute 27, 10031009 (1969).Google Scholar
10. Maloney, J.L. and Garrison, W.M. Jr., Scripta Metallurgica 23, 20972100 (1989).Google Scholar
11. Liu, W.J. and Jonas, J.J., Metallurgical Transactions A 20, 13611374 (1989).Google Scholar
12. Liu, W.J., Yue, S. and Jonas, J.J., Metallurgical Transactions A 20, 19071915 (1989).Google Scholar
13. Kubashewski, O., Evans, E.L. and Alcock, C.B., Metallurgical Thermochemistrv, 4th ed. (Pergamon Press, London, 1967).Google Scholar
14. Darken, L.S. and Gurry, R.W., Physical Chemistry of Metals (McGraw Hill, New York, 1953).Google Scholar
15. Brooksbank, D. and Andrews, K.W., Journal of Iron and Steel Institute 10, 246 (1972).Google Scholar
16. Ashby, M.F. and Ebeling, R., Transactions of AIME 236, 1396 (1966).Google Scholar
17. ASTM E813-81, in Standard Test Method for Jic, a Measure of Fracture Toughness, Annual Book of ASTM Standards Section E, (American Society of Testing and Materials, Philadelphia, PA 1983), p. 762,.Google Scholar