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http://dx.doi.org/10.7777/jkfs.2012.32.1.032

The Repeat Heat Treatment Behavior of Double Remelted Fe-Co Ultra-high Strength Steel. - Part. 1 Microstructure Control  

Yoon, Bo-Hee (Department of advanced material engineering, Chungnam national university)
Park, Kyoung-Tae (Graduate school of green energy technology, Chungnam national university)
Lee, Tae-Hyuk (Department of advanced material engineering, Chungnam national university)
Kim, Jae-Hoon (Department of mechanical engineering design, Chungnam national university)
Kim, Hong-Kyu (Agency for defense development of Korea)
Lee, Seong (Agency for defense development of Korea)
Lee, Jong-Hyeon (Graduate school of green energy technology, Chungnam national university)
Publication Information
Journal of Korea Foundry Society / v.32, no.1, 2012 , pp. 32-37 More about this Journal
Abstract
In this study, microstructural evaluation was carried out on secondary hardening type ultrahigh strength steel, Fe-Co-Ni composition. This paper as a first part of whole research presented the microstructural behavior by cyclic heat treatment. The cyclic heat treatment method includes normalizing, stress relieving, solution treatment and aging. Especially, solution treatments performed triple times to get maximized solution hardening. Phase transformation and microstructure were observed by using optical microscope (OM), Electron back-scattered diffraction (EBSD) and X-ray stress analyzer. During the triple solution treatment, size of grain boundary was dramatically decreased by generating a packet from the martensite transformation of residual austenite in the inner part of grain, whereas the hardness increase was not significant.
Keywords
Ultra high strength steel; Fe-Co-Ni; Microstructure;
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  • Reference
1 Y. Asayama: AISM, "Maraging steels recent development and application", 47 (1988) 295-302
2 G. Malakondaiah, M. Srinitlas and P. Rama Raot: Progress in Materials Science, "Ultrahigh-Strength low alloy steels with enhanced fracture toughnes", 42 (1997) 209-242   DOI   ScienceOn
3 Raghavan Ayer, Machmeier: J. Metall. Trans. A, "Transmission electron microscopy examination of hardening and toughening phenomena in Aermetl00", 24A (1993) 1943-1993
4 J. P. Campbell, K. T. Venkateswara Rao, and R. O. Ritchie: Metal. and Mat. trans. A, "The Effect of Microstructure on Fracture Toughness and Fatigue Crack Growth Behavior in γ- Titanium Aluminide Based Intermetallics", 30A (1999) 563- 577
5 M. J. Yokota, G. Y. Lai : J. Metall. trans. A, "Toughness of Lath vs Plate Martensites", 6A (1975) 1975-1835
6 Liu Y. j., Li Y. M., Tan Y. H. and Huang B. Y.: Inter. J. Iron and Steel Research "Apparent Morphologies and Nature of Packet Martensite in High Carbon Steels", 13 (2006) 40-46
7 James F. Shackelford : Pearson education inc., 6th edition, "Introduction to materials science for engineerings" Chap. 6 (2005) 186-285
8 S. Morito, M. Saito, T.Ogawa, T.Furuhara and T.Maki : ISIJ Inter, "Effect of austenite grain size on morphology and crystallography of lath martensite in low carbon steels", 45(1) (2005) 91-94   DOI
9 W. D. Callister : 2nd ed. Wiley & Sons, "Fundamentals of Materials Science and Engineering", 32 (2006) 252-257
10 Zhao, Z, Zhong, B J.: Aeronaut. Mater. China, "A Study of the Mechanism of Overage Behavior in a Secondary Hardening Steel", 8(2) (1988) 8-13
11 H. Kwon, C. M. Kim, K. B. Lee, H. R. Yang, and J. H. Lee : J. Metall. Trans. A, "Effects of Co and Ni on Secondary Hardening and Fracture Behavior of Martensitic Steels Bearing W and Cr", 29A (1998) 397-401