Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
권호 표지

Creep Crack Propagation Properties of Rotor Steel under Constant Load and Constant Ct Condition

일정하중 및 일정Ct에서 로터강의 크리프 귤열전파 특성

  • 정순억 (경상대학교 수송기계공학부, 해양산업연구소)
  • Published : 2001.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

The creep crack growth properties in 3.3NiCrMoV steel were investigated at 55$0^{\circ}C$ by using CT specimen under constant load and constant Ct condition that was held during crack growth of Imm distance. Ct lelied on load line displacement rate, C＊usually increased with crack length though load is reduced in order to maintain constant Ct value as crack growth and appeared scatter band. At constant load and Ct region, crack growth slope was 0.900 and 0.844 each, on the other hand C＊ slope was 0.480. Fully coalesced area(FCA) ahead of crack tip increased as Ct increase to the critical value, and after that value FCA decreased. For the tertiary creep stage of crack growth test, the most of displacement was due to the steady state creep, except only small part due to the primary creep and other effects. Therefore, tests were mainly interrupted in the tertiary stage to obtain high value of Ct.

Keywords

References

  1. Sellars, C. M., 'Creep Strength in Steel and High Temperature Alloys,' pp. 20, 1974
  2. 백남주, 이상배, 이민우, '고응력 상태에 있는 316 스테인레스강의 Creep 변형기구에 관한 연구,' 한국정밀공학회지, 제2권, 제1호, pp. 53-61, 1985
  3. 이강용, 김종성, '직선 균열강체 함유물을 내포하는 크립 재료의 균열해석,' 한국정밀공학회지, 제15권, 제7호, pp. 91-97, 1998
  4. 서성원, 신용승, 유헌일, '피로균열 성장거동에 관한 연구,' 한국정밀공학회지, 제9권, 제1호, pp. 106-117, 1992
  5. 백운봉, 윤기봉, 이해무, 서창민, 'CrMo강 용접계면 균열의 크리프-피로 균열성장 거동,' 대한기계학회 논문집 A권, 제24권, 제12호, pp. 3088-3095, 2000
  6. 윤기봉, 김광웅, 백운봉, '저합금강 용접부의 크리프 균열 성장거동 모델링,' 대학기계학회 논문집 A권, 제22권, 제12호, pp. 2153-2162, 1998
  7. Saxena, A., 'Creep Crack Growth under NonSteady State Conditions,' Fracture Mechanics ASTM STP, 905, pp. 185-201, 1986
  8. Taira, S., Ohtani, R., Komatsu, T., 'Application of J-Integral to High Temperature Crack Propagation(Part I - Fatigue Crack Propagation),' Jouranl of Engineering Materials and Technology, Vol. 101, pp. 154-161, 1979
  9. Hutchinson, J. W., 'The Mechanics and Physics of Solids,' Vol. 16, pp. 337-347, 1968 https://doi.org/10.1016/0022-5096(68)90021-5
  10. Saxena, A., Han, J. and Banerji, K., 'Creep Crack Growth Behavior in Power Plant Boiler and Steam Pipe Steels,' Journal of Pressure Vessel Technology, Vol. 110, pp. 137-146, 1988
  11. Schwalbe, K. H., Hellmann, D., 'Application of the Electrical Potential Method to Crack Length Measurements Using Johnson's Formula,' JTEVA, Vol. 9, No. 3, pp. 218-221, 1981 https://doi.org/10.1520/JTE11560J
  12. Saxena, A., 'Evaluation of C* for the Characterization of Creep- Crack-Growth Behavior in 304 Stainless Steel,' Fracture Mechanics,Twelfth Conference, ASTM STP700, pp. 131-151, 1980
  13. Ernst, H. A., 'Unified Solution for J Ranging Continuously from Pure Bending to Pure Tension,' Fracture Mechanics, Vol. 1, ASTM STP791, pp. 1499-1519 1983
  14. Hermann, R., 'Fracture at High Temperature,' Springer-Verlag, pp. 263-298, 1986
  15. Hour, K. Y. and Stubbins, J. F., 'Fatigue Crack Growth Behavior of Alloy 800H at Elevated Temperature,' Journal of Engineering Materials and Technology, Vol. 113, pp. 271-279, 1991
  16. Tada, H., Paris, P. and Irwin, G. R., 'The Stress Analysis of Cracks Handbook,' Del Research Corp., Helletown, 1973
  17. Hong, S. H., 'Creep Crack Growth and Micromechanism,' KAIST Ph.D, 1989