Hostname: page-component-745bb68f8f-s22k5 Total loading time: 0 Render date: 2025-01-12T08:12:44.503Z Has data issue: false hasContentIssue false
  • English
  • Français

Electron Microscopy Observations of Precipitation During Tempering of Vasco X-2M Steel and its Relation to Impact Toughness

Published online by Cambridge University Press:  25 February 2011

James E. Krzanowski
James E. Krzanowski*
Affiliation:
Army Materials Technology Laboratory, Arsenal St., Watertown, MA 02172
Get access

Abstract

Vasco X-2M is a low carbon tool steel which is being considered for critical gear applications. Since toughness is an important property for these applications, the Charpy V-notch impact energy was tested as a function of tempering temperature and found to drop considerably at 480C temper and above. A TEM investigation was carried out in order to better understand the results of this test. The precipitation sequence of carbides was examined along with their morphology, structure and orientation relation to the matrix. The precipitation of the intralath M3C carbides occurred on quenching from austenite. These carbides were then present in all tempered samples. M2C carbides were observed at 480C and 590C temper, and evidence for precipitation of these carbides was based on hardness data at 480C temper and TEM observations at 590C temper. After aging 200h at 590C, the ceitientite was observed to be in the process of transforming in an in-situ manner to an M7C3 carbide. The minimum in the Charpy impact energy was found to occur when both coarse M3C and a very fine dispersion of M2C were present in the microstructure.

Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 62: Symposium Q – Materials Problem Solving with the Transmission Electron Microscope , 1985 , 273
Copyright
Copyright © Materials Research Society 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Lement, B.S., et al., Trans. AIME 46, 851 (1954).Google Scholar
2. Capus, J.M., J. Iron and Steel Inst. 201, 53 (1963).Google Scholar
3. Sarikaya, H., Jhingan, A.K., and Thomas, G., Metall. Trans. 14A, 1121 (1983).Google Scholar
4. Fopiano, P.J., Kula, E.B., and Oliver, S.A., AMMRC TR 77–8.Google Scholar
5. Krzanowski, J.E., and Fopiano, P.J., AMMRC Technical Report, in press.Google Scholar
6. Haynes, A.G., Heat Treatment of Steels, Special Rep. 95, 13–23, ISI (1966).Google Scholar
7. Bagaryatski, Y.A., Dokl. Akad. Nauk SSSR 73, 1161 (1950).Google Scholar
8. Stiller, et al., Acta metall. 32, 1457 (1984).Google Scholar
9. Speich, G.R., Trans. AIME 245, 2553 (1969).Google Scholar
10. Raynor, D., Whiteman, J.A., and Honeycombe, R.W.K., J. Iron and Steel Inst. 204, 1114 (1966).Google Scholar
11. Speich, G.R., Dabkowski, D.S., and Porter, L.F., Metall. Trans. 4, 303 (1973).Google Scholar