Creep Rupture Strength and Microstructure of Low C-10Cr-2Mo Heat-Resisting Steels with V and Nb
Tóm tắt
The new ferritic heat-resisting steels of 0.05C-10Cr-2Mo-0.10V-0.05Nb (Cb) composition with high creep rupture strength and good ductility have already been reported. The optimum amounts of V and Nb that can be added to the 0.05C-10Cr-2Mo steels and their effects on the creep rupture strength and microstructure of the steels have been studied in this experiment. The optimum amounts of V and Nb are about 0.10 pct V and 0.05 pct Nb at 600 °C for 10,000 h, but shift to 0.18 pct V and 0.05 pct Nb at 650 °C. Nb-bearing steels are preferred to other grades on the short-time side, because NbC precipitation during initial tempering stages delays recovery of martensite. On the long-time side, however, V-bearing steels have higher creep rupture strength. By adding V to the steels, electron microscopic examination reveals a stable microstructure, retardation during creep of the softening of tempered martensite, fine and uniform distribution of precipitates, and promotion of the precipitation of Fe2Mo.
Tài liệu tham khảo
R. T. King and L. Egnell:International Conf. on Ferritic Steels for Fast Reactor Steam Generators, pp. 74–81, BNES, London, 1978.
G. Gung, F. Pellicani, J. Houts, and B. Duquaire:ibid, pp. 164-70.
T. Yukitoshi, K. Nishida, T. Oda, and T. Daikoku:J. Pressure Vessel Technol., 1976, vol. 98, pp. 173–78.
T. Fujita, K. Asakura, and T. Sato:Trans. Iron Steel Inst. Jpn., 1979, vol. 19, pp. 605–13.
T. Fujita:Proceedings of the International Conf. on the Strength of Metals and Alloys, Supplement toTrans. Jpn. Inst. Met., 1968, vol. 9, pp. 167–69.
T. Fujita, K. Yamashita, and H. Miyake:Trans. Iron Steel Inst. Jpn., 1980, vol. 20, pp. 384–91.
K. Asakura, T. Fujita, and K. Yamashita:Tetsu-To-Hagane, 1980, vol. 66, no. 9, pp. 1375–84.
T. Fujita and N. Takahashi:Trans. Iron Steel Inst. Jpn., 1978, vol. 18, pp. 269–78.
L. Egnell:High-Temperature Properties of Steels, ISI Publication 97, 1967, pp. 153-58.
M. Caubo and J. Mathonet:Rev. Metall., 1969, vol. 66, pp. 345–60.
J. W. Bennett and K. E. Horton:Metall. Trans. A, 1978, vol. 9A, pp. 143–49.
J. J. Laidler, J. J. Holmes, and J. W. Bennett:International Conf. on Radiation Effects in Breeder Reactor Structural Materials, AIME, AZ, 1977, pp. 41-52.
J. J. Huet, A. Delbrassine, Ph. Van Asbroeck, and W. Vandermeulen:ibid, 1977, pp. 357–65.
F. B. Pickering: Spec. Rep. No. 64, ISI, pp. 23–43, 1959.
V. P. Gupta and P. R. Dhar:J. Iron Steel Inst., 1963, vol. 201, pp. 213–16.
K. A. Ridal and A. G. Quarrell:J. Iron Steel Inst., 1960, vol. 195, pp. 307–14.
S. W. Shaw and A. G. Quarrell:J. Iron Steel Inst., 1957, vol. 185, pp. 10–22.
K. C. Mills, B. B. Argent, and A. G. Quarrell:J. Iron Steel Inst., 1961, vol. 197, pp. 9–21.
J. Koutsky:J. Iron Steel Inst., 1967, vol. 205, pp. 763–68.
T. Nishida and M. Tanino:J. Jpn. Inst. Met., 1965, vol. 29, pp. 728–34.