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http://dx.doi.org/10.12656/jksht.2010.23.3.156

Study on the Embrittlement of the Mod. 9Cr-1Mo Steel Tempered at $550^{\circ}C$  

Gu, Ji-Ho (School of Materials Science and Engineering, Changwon National University)
Shin, Jong-Ho (School of Materials Science and Engineering, Changwon National University)
Hur, Sung-Kang (Doosan Heavy Industry)
Publication Information
Journal of the Korean Society for Heat Treatment / v.23, no.3, 2010 , pp. 156-162 More about this Journal
Abstract
The modified 9Cr-1Mo steel (P91 steel) is very popular as a boiler tube material of the USC (Ultra-Supercritical) power plants. The steels were tempered in the temperature range of 400 to $650^{\circ}C$ and the mechanical tests, such as impact and hardness tersts were performed at the room temperature for the tempered steels. A drop in the impact value (embrittlement) and the hardeness increase were simultanously observed in the range of temperature between $475^{\circ}C$ and $600^{\circ}C$, particularly at $550^{\circ}C$. TEM observation shows the hardening was caused by $M_2C$, resulting in the embrittlement. And the maximum volume fraction of $M_3C$ was also observed at $550^{\circ}C$, Therefore, the embrittlement seems to be caused by both the $M_2C$ and $M_3C$.
Keywords
Modified 9Cr-1Mo steel; Embrittlement; $500^{\circ}C$; $M_2C$;
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  • Reference
1 S. Yamasaki and H. K. D.H Bhadeshia : Mater. Sci. and Tech, 19 (2003) 723.   DOI   ScienceOn
2 R. G. Baker andJ. Nutting: J. of the Iron and Steel Intitute, VoL 192 (1959) 257.
3 ASM Handbook Vol 11 : Failure Analysis and Prevention (2002) 691.
4 H. Kwon and C. H. Kim: Metall. Trans. A 14 (1983) 1389.
5 R. Viswanathan : Damage Mechanism and Life Assessment of High Temperature Components, ASM International (1989) 77
6 ASM Handbook, Vol. 1, Properties and Selection: Irons and Steels (1978) 698.
7 Thermally Induced Embrittlement of Steels, ASM Specialty Handbook: Carbon and Alloy Steels, J. R. David Ed., ASM International (1996) 309.
8 Kon Bae Lee, Heong Ryeal Yang and Boon Kwon : J. of the Korean Inst. of Met. & Mater. 33(9) (1995) 1250.
9 Kon Bae Lee, Heong Ryeal Yang and Hoon Kwon : J. of the Korean Inst. of Met. & Mater., 34(7) (1996) 805.