Embrittlement Behavior of Isothermally Heat-Treated T/P92 Steel at 350°C


Article Preview

P92 steels as well as P91 are widely used as boiler tube materials of ultra super critical (USC) power plants these days. And thus embrittlement is very important for structural integrity of the USC plants. The embrittlement was observed when P92 (Modified 9Cr-1.8W-0.5Mo-V-Nb) steels were quenched to and held at the temperature of 320 to 350°C, which were the temperatures intermediate between Ms and Mf, and then air-cooled. Nearly same kind of the embrittlement had been observed with the T/P91 steels and a theory had been proposed to explain the mechanism of the embrittlement by us. From the theory, the embrittlement might be caused by the brittle martensite which is freshly formed during air-cooling. We tried to apply the theory for the embrittlement of the T/P92 steel. The behaviors of the embrittled T/P92 steel were explained well by the theory.



Key Engineering Materials (Volumes 345-346)

Edited by:

S.W. Nam, Y.W. Chang, S.B. Lee and N.J. Kim




J. M. Koo et al., "Embrittlement Behavior of Isothermally Heat-Treated T/P92 Steel at 350°C", Key Engineering Materials, Vols. 345-346, pp. 465-468, 2007

Online since:

August 2007




[1] S. K. Hur, et al, Mater. Sci. Forum 475-479, 4 (2003).

[2] R. M. Horn and R.O. Ritchie, Metall. Trans. A 9, 1039 (1978).

[3] J. Cermark, J. Kucera, B. Million, J. Krumpos, Kov. Mater., 18, 537 (1980).

[4] D. A Porter & K.E. Easterling, Phase Transformation on Metal and Alloys, p.415, CRC Press, Taylor & Francis Group, United kingdom (2004).

[6] S.H. Yoon, K.B. Lee, S.I. Hong and H. Kwon, J. Kor. Inst. Met. & Mater. 32, 1250 (1994).

[7] J.R. Davis Davis & Associates, Elevated temperature mechanical properties of carbon and alloy steel, p.107, ASM Special Handbook ed. by Inter. ASM, America (1998).