Browse > Article
http://dx.doi.org/10.3365/KJMM.2018.56.3.221

Effect of Hot Forging and Heat Treatment on the Microstructure and Mechanical Properties of Cr Steel  

Lee, Dong Jun (Materials Deformation Department, Korea Institute of Materials Science (KIMS))
Kwon, Yong-Nam (Materials Deformation Department, Korea Institute of Materials Science (KIMS))
Kim, Min Suk (Materials Deformation Department, Korea Institute of Materials Science (KIMS))
Ku, Ga Eun (Materials Deformation Department, Korea Institute of Materials Science (KIMS))
Heo, Sang Hyun (Research Institute Attached)
Kim, Nam Yong (Research Institute Attached)
Lee, Jin-Mo (Research Institute Attached)
Publication Information
Korean Journal of Metals and Materials / v.56, no.3, 2018 , pp. 221-226 More about this Journal
Abstract
In this study, the effects of hot forging and heat treatment (quenching and tempering) of cast Cr alloy steel on the microstructures and mechanical properties were investigated. The hot forging was performed at a compressive ratio 0.5 at $1,250^{\circ}C$. The heat treatment process was quenching ($860^{\circ}C$ for 2 hours and water quenching) and tempering ($655^{\circ}C$ for 2 hours and air cooling). The microstructures of the hot forged specimen showed bainite, pearlite and ferrite mixed phases with high tensile strength, but showed low fracture toughness. The heat treated specimens after hot forging showed tempered martensite microstructure and high fracture toughness but relatively low yield and tensile strengths. After tensile and fracture toughness tests, the cast and the hot forged specimens both showed cleavage fracture surfaces, which occurred between lamellar structures. However, the heat treated specimen had a ductile fracture surface with dimple shaped fractures. From these results, we could conclude that the high fracture toughness was caused not by the cleavage fracture mode in the pearlite and bainite phases, but delayed fracture due to a ductile fracture mode in the tempered martensite phase.
Keywords
Cr steel; heat treatment; fracture toughness; microstructure; tempered martensite;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 X. Z. Zhang and J. F. Knott, Acta Mater. 47, 3483 (1999).   DOI
2 P. Bowen, S. G. Druce, and J. F. Knott, Acta Metall. 34, 1121 (1986).   DOI
3 P. Bowen, S. G. Druce, and J. F. Knott, Acta Metall. 35, 1735 (1987).   DOI
4 S.-Y. Lee, S.-I. Lee, and B. Hwang, Korean J. Met. Mater. 54, 637 (2016).   DOI
5 T. S. Wang, J. Yang, C. J. Shang, X. Y. Li, B. Zhang, and F. C. Zhang, Scripta Mater. 61, 434 (2009).   DOI
6 A. Salemi and A. Abdollah-zadeh, Mater. Charact. 59, 484 (2008).   DOI
7 W. S. Lee and T. T. Su, Mater. Proc. Tech. 87, 198 (1999).   DOI
8 E. K. Tschegg and S. Suresh, Metall. Trans. A 19, 3035 (1988).   DOI
9 J. J. Hoyos, H. R. Salva, J. M. Vélez, and A. A. Ghilarducci, Mater. Sci. Eng. A 660, 148 (2016).   DOI
10 K.-H. Lee, S.-G. Park, M.-C. Kim, and B.-S. Lee, Mater. Sci. Eng. A 534, 75 (2012).   DOI
11 G.-H. Kim, J.-H. Jang, S.-H. Kim, B.-J. Kim, K.-Y. Sohn, and D.-G. Nam, Korean J. Met. Mater. 55, 559 (2017).
12 S. Sankaran, V. Subramany Sarma, K. A. Padmanabhan, G. Jaeger, and A. Koethe, Mater. Sci. Eng. A 362, 249 (2003).   DOI
13 N. N. Jia, K. Guo, Y. M. He, Y. H. Wang, J. G. Peng, and T. S. Wang, Mater. Sci. Eng. A 700, 175 (2017).   DOI
14 C. Wang, H. Qiu, Y. Kimura, and T. Inoue, Mater. Sci. Eng. A 669, 48 (2016).   DOI
15 Y. Kimura, T. Inoue, F. Yin, and K. Tsuzaki, ISIJ International 50, 152 (2010).   DOI
16 T. Inoue, Y. Kimura, and S. Ochiai, Scripta Mater. 65, 552 (2011).   DOI
17 A. Abdollah-Zadeh, A. Salemi, and H. Assadi, Mater. Sci. Eng. A 483-484, 325 (2008).   DOI
18 E. Paravicini Bagliani, M. J. Santofimia, L. Zhao, J. Sietsma, and E. Anelli, Mater. Sci. Eng. A 559, 486 (2013).   DOI
19 J. Feng, T. Frankenbach, and M. Wettlaufer, Mater. Sci. Eng. A 683, 110 (2017).   DOI