JOURNAL BROWSE
Search
Advanced SearchSearch Tips
Evaluation of Degradation Behavior of the Long-Term Serviced Boiler Header
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
Evaluation of Degradation Behavior of the Long-Term Serviced Boiler Header
Gwon, Jae-Do; Bae, Yong-Tak; Choe, Seong-Jong;
  PDF(new window)
 Abstract
The degradation of a boiler header constructed by a material, 1Cr-0.5Mo steel in a fossil power plant is observed when the header is exposed for a long period to the high temperature and pressure. The present investigations are for evaluating the effect of the degradation on the material, such as its strength changes. Reheat-treated metal is used to compare the mechanical properties of the degraded and that of reheat-treated materials. Through the investigation, following results are obtained 1) the area ratio of ferrite in the reheat-treated material is larger than that of the degraded material, 2) the hardness and tensile strength of the degraded material are lower than that of the reheat-treated material, 3) the ductile-brittle transition temperature(DBTT) increased toward high temperature region, 4) the fatigue crack growth rate(FCGR) of the degraded material is higher than that of the reheat-treated material in the region of low ΔK value while FCGR of the both materials are similar in high ΔK region.
 Keywords
Boiler Header;1Cr-0.5Mo Steel;Degradation;Reheat-Treated MateriaI;Fatigue Crack Growth;
 Language
Korean
 Cited by
 References
1.
Watanabe, Y., and Shoji, T., 1991, 'The Evaluation of in-service Materials Degradation of Low Alloy Steels by The Electrochemical Method,' Met. Trans., Vol. 22A, pp. 2097-2106 crossref(new window)

2.
Abdel-Latif, A. M., Corbett, J. M., Sidey, D., Taplin, D. M. R., 1981, 'Effect of Microstructural Degradation in Creep Life Prediction of 2.25Cr-1Mo Steel,' Proceeding of the 5th ICF, Cannes, France, Vol. 4, pp. 1613-1620

3.
Burghad, H. C., McCann, D. R., 1984, 'Fractographic Analysis of a Steam Turbine Disk Failure,' ASTM STP 827, pp. 106-114

4.
Katsumata, M., Takada, H., et al., 1981, 'Temper Embrittlement in Pressure Vessel Steel,' JHPI, Vol. 12, No. 3, pp. 8-14

5.
材上賀國, 1983, '壓力容器用Cr-Mo鋼の燒屯胞性に關する硏究,' 大阪大學工學部 博士學位論文

6.
Biss, V. A., and Wada, T., 1985, 'Microstructural Changes in 1Cr-0.5Mo Steel after 20 Years of Services,' Met. Trans., Vol. 16A, pp. 109-114 crossref(new window)

7.
Nishizaka, Y., Hara, Y., Hori, A., Tsukahara, H.,Miyano, K., Wada, T., Cox, T. B., 1985, 'Changes in Microstructure and Mechanical Properties of Cr-Mo Reactor Vessel Steels During Long-Term Services,' Journal of Pressure Vessel Technology, Vol. 107, pp. 285-294

8.
JIS G 0552 (ISO 643), 1998, 'Methods of Ferrite Grain Determination Test for Steel,' pp. 1-23 (in japanese)

9.
권재도, 1992, '장기사용 Cr-Mo강 열화재에 파괴인성평가와 수명예측,' 대한기계학회논문집, 제16권, 18호, pp. 1421-1426

10.
권재도, 진영준, 류승우, 장순식, 1993, '다단계 모의 열화재의 재료강도 평가와 수명예측,' 대한기계학회논문집, 제17권, 제9호, pp. 2271-2279