Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Effects of Inclusions on Fracture Toughness for 1%CrMoV Rotor Steel

1%CrMoV 로터강의 파괴인성에 미치는 개제물의 영향

  • Published : 2000.09.01
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Abstract

This thesis studied that seven kinds of residual elements(inclusions) had influenced on fracture toughness($K_{IC}$) obtained by Begley-Logsdon and Rolfe-Novak model equation using tensile an d impact test data of I%CrMoV HP(high pressure) rotor steel. $K_{IC}$ design curve of ASME and fracture surface by SEM were also considered, obtained results are summarized as follows $K_{IC}$ was linearly increased with increase of temperature, effect of the inclusions was significantly over FATT. $K_{IC}$ at lower shelf temperature was quantitatively related to yield strength and was agreed well with Begley's equation. It was difficult to determine $K_{IC}$ because of specimen size and tester capacity at upper shelf temperature, but for this view point Rolfe-Novak's equation was useful. The degree of brittle fracture was dependent on FATT fundamentally, adding S, Sb to matrix decreased impact energy and adding Cu, As increased yield(tensile) strength, and the influence of the others minority inclusion was comparatively insignificant.

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References

  1. 송삼홍, 강명수, 1997, '터빈용 Cr-Mo-V강의 고온 환경변화에 따른 피로거동에 관한 연구,' 대한기계학회논문집, Vol. 21, No. 1, pp. 173-179
  2. 홍성호, 조현춘, 1994, '3.5Ni-Cr-Mo-V강의 크리프 수명예측에 재질열화 및 오스테나이트 결정립 조대화가 미치는 영향,' 대한기계학회논문집, vol. 18, No. 11, pp. 2837-2845
  3. 정남용, 김문영, 김종우, 1999, '발전용 가스터빈 고온 부재의 탄소성 J적분 파괴인성 평가,' 대한기계학회논문집, Vol. 23, No. 10, pp. 1837-1844
  4. McMahon, C. J. and Gentner, D. H., 1977, Problems of Alloy Design in Pressure Vessel Steels in Fundamental Aspects of Structural Alloy Design, McGraw-Hill, pp. 295-322
  5. McMahon, C. J. et al., 1980, 'The Effect of Composition and Microstructure on Temper Embrittlement in 21/4Cr-1Mo Steels,' ASME J. Engg.Mater.Tech., Vol. 102
  6. Viswanathan ,R. and Jaffee, R. I., 1982, '21/4Cr-1Mo Steels for Coal conversion Pressure Vessels,' ASME J., Engg.Mater.Tech., Vol. 104, pp. 220-226
  7. Viswanathan, R. and Jaffee, R. E., 1985, 'Metallurgical Factors Affecting the Reliability of Fossil Steam Turbine Rotors,' ASME J. Engg.Gas.Turbines and Power, vol. 107, pp. 642-651
  8. ASM, 1979, 'Properties and Selection: Non-Ferrous Alloys and Pure Metals,' Metals Hand-book, Ninth Edition, pp. 239-241
  9. George, E. D., 1984, 'Mechanical Metallurgy', International Student Edition, pp. 497-502
  10. Raghupathy, V. P., 1982, 'The Effct of Sulphide Inclusioons of Fracture Toughness and Fatigue Crack Growth in 12wt% Cr Steel,' Chapman and Hall Ltd., pp. 2112-2126
  11. Begley, J. A. and Logsdon, W. A., 1971, 'Correlation of Fracture Toughness and Charpy Properties of Rotor Steels,' Scientific Paper 71-1E7-MSLRP, Westing-house Research Laboratories
  12. Rolfe, S. T. and Novak, S. R., 1970, 'Slow Bend KIC Testing Medium Strength, High Toughness Steels,' STP463,ASTM, ASTM, Philadephia, p. 124
  13. Iwadate, T., Watanabe, J. and Tanaka, Y., 1985, 'Prediction of the Remaining Life of High Temperature/Pressure Reactors Made of Cr-Mo Steels,' Trans.ASME, J.Pressure Vessel Tech., Vol. 107, pp. 230-238
  14. Coulon, A., 1988, 'The Role of Trace Elements in a Martensitic Steel,' Recent Developments in Rotor Forging Steels, Iron and Steel Society, Inc., AIME, pp. 119-130
  15. Lenel, U. R. and Kuott, B. R., 1987, 'Micro-structure Composition Relationships and Ms Temperatures in Fe-Cr-Mn-N Alloys,' Metallurgical Transactions A, Vol. 18A, pp. 767-775 https://doi.org/10.1007/BF02646919