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

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of Stress Corrosion Strength According to Crystal Structure of 12Cr Alloy Steel Used Steam Turbine Blade

증기터빈 블레이드용 12Cr 합금강의 결정구조에 따른 응력부식강도 평가

  • Published : 2008.11.01
Download PDF
⟨ Previous Next ⟩

Abstract

It was found that more than 60% of the steam turbine blade damages occurred under the condition alternatively repeated wet and dry of vapor and condensed vapor at the lower pressure stage. And also, it has been well known that both the mechanical properties and environmental strength of the steam turbine blade can be changed by the crystal structure. However, in spite of these common facts, it is difficult to find out the quantitative results including the particular environmental condition as well as the actual service conditions. In this study, as a fundamental investigation to provide design information and reliability evaluation of the 12Cr alloy steel used for a steam turbine blade, stress corrosion strength of the 12Cr alloy steel of which its crystal structure is different was assessed under $2.5{\sim}3.5wt.%$ NaCl solution at 90oC. From the results, S-t curves for predicting damage life and design criterion of the 12Cr alloy steel including corrosion environment as well as S.C.C. condition were obtained.

Keywords

References

  1. JSME, 1984, "Corrosion and Fracture," JSME, Japan Industrial Publish Co. pp. 71~74
  2. Technical Report of Korea Electric Power Research Institute(KEPRI), 1987, " A Study on the Prediction of Fatigue Life for Turbine Rotor," Korea Electric Power Research Institute(KEPRI)
  3. Otani, 1984, "A Chair of Material Strength-strength in Environment and High Temperature," Ohm Co., pp. 39~82
  4. Dongho Bae and Byungbok Choi, 2005, “Evaluation of Degree of Sensitization and Corrosion Characteristics for Artificially Sensitized Austenitic STS304,” Solid State Phenomena Vol.110, Trans. Tech. Publication, pp. 249 ~253
  5. ASTM, 1995, "Standard Test Method for Measurement of Fatigue Crack Growth Rates," ASTM E647-95, pp. 578~614
  6. “New Material for Advanced Steam Turbines," 1992, EPRI Report TR-100979, Vol. 6
  7. Timo, D. P., Sarney, G. W., 1967, "The Operation of Large Steam Turbines to Limit Cyclic Thermal Cracking," ASME 67-WA/PWR-4, pp. 3~15
  8. Lamberson, J. A., Gernnan, C. W., 1997, "Expanded High Technology Control for Steam Turbines," Joint Power Generation Conference, Vol.2, pp. 201~211
  9. Matsumoto, H., Kato, F., 1982, "Turbine Control System Based on Prediction of Rotor Thermal Stress," IEEE Transactions on Power Apparatus and System, Vol. PAS-101, No. 8.,pp. 2504~2512 https://doi.org/10.1109/TPAS.1982.317654
  10. Viswanathan, R., 1989, "Damage Mechanisms and Life Assessment of High Temperature Components," ASM INTERNATIONAL, pp. 265~328
  11. Koji, Y., Kazuo, K., 1994, "Parameter Analysis for Time Dependent Low-Cycle Fatigue Life," Journal of Eng. Mat. & Technology, Vol. 116, pp. 479~482 https://doi.org/10.1115/1.2904316
  12. Mora, J., Retzlaff, K., M., 1979, "Design and Operation of Large Fossil-Fueled Steam Turbines Engaged in Cyclic Duty," AMERICAN Society of Mech. Eng. Joint Power Generation Conference, pp. 3~18
  13. Elbridge Z. Stowell, “Stress and Strain Concentration at a Circular Hole in An Infinite Plate,” 1950, NACA Technical Note 2073