Browse > Article
http://dx.doi.org/10.12656/jksht.2013.26.5.241

Effects of C, Mo and Cr on Hardenability and Mechanical Properties of Boron-Bearing Steels  

Yim, H.S. (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
Jung, W.Y. (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
Hwang, B. (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
Publication Information
Journal of the Korean Society for Heat Treatment / v.26, no.5, 2013 , pp. 241-247 More about this Journal
Abstract
Hardenability and mechanical properties of boron-bearing steels containing C, Mo and Cr were investigated in this study. Using quench dilatometer, the steel specimens were cooled down to room temperature at different cooling rates to construct continuous cooling transformation diagrams and then the transformation products from austenite were examined. A critical cooling rate was introduced as an index to quantitatively evaluate the hardenability. The C addition to boron-bearing steels did not significantly affect hardenability compared to boron-free steels although it increases the hardenability. With the same content, the Mo addition largely increased the hardenability of boron-bearing steels than the Cr addition because it decreased both the transformation start and finish temperatures at low cooling rates. In particular, the Mo addition completely suppressed the formation of eutectoid ferrite even at the slow cooling rate of $0.2^{\circ}C/s$, whereas the Cr addition nearly suppressed it at the cooling rates above $3^{\circ}C/s$.
Keywords
Boron steel; Hardenability; Mechanical properties; C; Mo; Cr;
Citations & Related Records
연도 인용수 순위
  • Reference
1 S. K. Banerji and J. E. Morral : Proc. Int. Symp. Boron in Steels, TMS-AIME, PA (1979).
2 D. H. Werner : Boron and Boron Containing Steels, Verlag Stahleisen mbH, Dusseldorf (1995).
3 D. V. Doane and J. S. Kirkaldy : Hardenability Concepts with Application to Steel, TMS-AIME, Warrendale, PA (1978).
4 Ph. Maitrepierre, D. Thivellier and R. Tricot : Metall. Trans. A, 6 (1975) 287.   DOI
5 Front of Research on Behavior of Boron in Steels, Iron Steel Inst. Jpn. (2003).
6 M. Ueno and T. Inoue : Trans. Iron Steel Inst. Jpn., 13 (1973) 210.
7 H. Asahi : ISIJ Int., 42 (2002) 1150.   DOI
8 B. Hwang, D. -W. Suh and S. -J. Kim : Scr. Mater., 64 (2011) 1118.   DOI   ScienceOn
9 L. Karlsson, H. Norden and H. Odelius : Acta Metall., 36 (1988) 1.   DOI   ScienceOn
10 X. L. He, Y. Y. Chu and J. J. Jonas : Acta Metall., 37 (1989) 147.   DOI   ScienceOn
11 S. Khare, K. Lee and H. K. D. H. Bhadeshia : Int. J. Mat. Res., 100 (2009) 11.   DOI
12 K. A. Taylor : Metall. Trans. A, 23 (1992) 107.   DOI
13 Standard Test Methods for Determining Hardenability of Steel, ASTM International, Designation: A 255-02 (2002).
14 G. Krauss, Principles of Heat Treatment of Steel, ASM Intl. (1989).
15 J. C. Ion and L. M. Anisdahl : J. Mat. Proc. Tech., 65 (1997) 261.   DOI   ScienceOn
16 B. C. De Cooman, J. G. Speer, I. Y. Pyshmintsev and N. Yoshinaga : Materials Design - The Key to Modern Steel Products, GRIPS media GmbH (2007).
17 D. J. Mun, E. J. Shin, Y. W. Choi, J. S. Lee and Y. M. Koo : Mater. Sci. Eng. A, 545 (2012) 214.   DOI   ScienceOn