SP-Creep 시험에 의한 고온 크리프 특성 평가 기술 개발(I) - 보일러 과열기 튜브 -

Development of Evaluation Technique of High Temperature Creep Characteristics by Small Punch-Creep Test Method (I) - Boiler Superheater Tube -

  • 백승세 (전북대학교 대학원 정밀기계공학과) ;
  • 나성훈 (전북대학교 대학원 정밀기계공학과) ;
  • 나의균 (군산대학교 기계공학부) ;
  • 유효선 (전북대학교 기계공학부, 자동차 신기술 연구소)
  • Baek, Seung-Se (Dept.of Precision Mechanical Engineering, Graduate School of Chonbuk National University) ;
  • Na, Seong-Hun (Dept.of Precision Mechanical Engineering, Graduate School of Chonbuk National University) ;
  • Na, Ui-Gyun (Faculty of Mechanical Engineering, Kunsan National University) ;
  • Yu, Hyo-Seon (Automotive New Technology Research Center, Dept.of Mechanical Engineering, Chonbuk National University)
  • 발행 : 2001.12.01


In this study, a small punch creep(SP-Creep) test using miniaturized specimen(10${\times}$10${\times}$0.5mm) is described to develop the new creep test method for high temperature structural materials. The SP-Creep test is applied to 2.25Cr-lMo(STBA24) steel which is widely used as boiler tube material. The test temperatures applied for the creep deformation of miniaturized specimens are between 550∼600$^{\circ}C$. The SP-Creep curves depend definitely on applied load and creep temperature, and show the three stages of creep behavior like in conventional uniaxial tensile creep curves. The load exponent of miniaturized specimen decreases with increasing test temperature, and its behavior is similar to stress exponent behavior of uniaxial creep test. The creep activation energy obtained from the relationship between SP-Creep rate and test temperature decreases as the applied load increases. A predicting equation or SP-Creep rate for 2.25Cr-lMo steel is suggested. and a good agreement between experimental and calculated data has been found.



  1. Mao, X., Takahashi, H. and Kodaira, T., 1991, 'Estimation of Mechanical Properties of Irradiated Nuclear Pressure Vessel Steel by use of Subsized CT Specimen and Small Punch Specimen,' Scripta Metallurgica, Vol. 25, pp. 2487-2490
  2. Ha, Jeong Soo and Fleury, Eric, 1998, 'Small Punch Tests on Steels for Steam Power Plants Ductile Brittle Transition Temperaure,' KSME International Jorunal, Vol. 12, No. 5, pp. 818-826
  3. JAERI-memo(62-193), 1987, '小型バンチ(SP)試險法(案),' 日本原子力硏究所, pp. 1-135
  4. Okada, A., Yoshiie, T., Kojima. S., Abe, K. and Kiritani, M., 1985, 'Correlation among a Variety of Miniaturized Mechanical Tests and their Application to D-T Neutron-Irradiated Metals,' Journal of Nuclear Materials, Vol. 133 & 134, pp. 321-325
  5. Manahan, M.P., Argon, A.S. and Harling, O.K., 1981, 'The Development of a Miniaturized Disk Bend Test for the Determination of Post-Irradiation Mechanical Properties,' Vol. 103 & 104, pp. 1545-1550
  6. Baik, Jai-Man, Kameda, J. and Buck, O., 1983, 'Small Punch Test Evaluation of Intergranular Embrittlement of an Alloy Steel,' Scripta METALLURIGICA, Vol. 17, pp. 1443-1447
  7. 竹田賴正, 高野角作, 藤田明次, 1988, '徵小ハンチ試驗による長時間使用Cr-Mo-V ロタ-の衝擊特性の推定,' 材料, 第 37卷, 第 421號, pp. 48-54
  8. 松下敬, 四迂美年, 庄子哲雄, 高橋秀明, 1989, 'ッャルピ-衝擊 試驗と小型パンチ試驗における碩面遷移學動の相關について,' 日本機術學會論文集(A編), 55卷, 515號, pp. 16191622
  9. Yu, Hyo-Sun, Na, Eui-Gyun, and Chung, Se-Hi, 1999, 'Assessment of Stress Corrosion Cracking Susceptibility by Small Punch Test,' Journal of Fatigue & Fracture of Engineering Materials & Structures, European Structural Integrity Society, Vol. 22, No 10, pp. 889-896
  10. 유효선, 백승세, 이송인 외 2인, 2000, '소형펀치-크리프 시험기 및 고온부재의 크리프 특성 평가방법,' 특허출원 제 24756호
  11. 유효선, 백승세, 이송인, 하정수, 2000, '미소시험편을 이용한 고온 크리프 특성 평가법 개발,' 대한기계학회 춘계학술대회논문집 A, pp. 43-48
  12. Jean-Paul Poirier, 1985, 'Creep of Crystal : High-Temperature deformation process in metals, ceramics and mineals,' Cambridge University Press, pp. 76-79
  13. 한국전력연구원, 1997, '고온재료의 크리프 손상 측정기술 개발' 보고서
  14. Evans, H. E., 1984, 'Mechanism of Creep Fracture,' Elsevier Applied Science Publishers, pp. 18-22
  15. Shih, C.F., 1977, 'A Stabel Computa tional Scheme for Stiff Time-Dependance Constitutive Equations,' 4th ed.,
  16. Kanter, J.J., 1938, Trans. AIME., Vol. 143