The creep life can be evaluated by the degree of grain deformation since the grains of Cr-Mo base material deform in the direction of stress. The grain deformation method using image-processing technique is developed for life assessment of in-service high temperature components. The new assessment model for the method is presented to apply to in-service components and is verified by interrupted creep test for ex-serviced material of 1Cr-0.5Mo steel. The proposed model, which is irrespective of stress direction, is to evaluate mean of the absolute deviation for the measured aspect ratios of the grains sections. [S0094-4289(00)00801-X]

Issue Section:
Technical Papers
Keywords:
creep, steel, grain boundaries, cavitation, boilers
Topics:
Creep, Deformation, Image processing
1.
Roberts, B. W., Ellis, F. V., and Henry, J. F., 1989, Remaining-Life Estimation of Boiler Pressure Parts, Volume 4: Metallographic Models for Weld-Heat-Affected Zone, EPRI CS-5588, pp. 37–39.
2.
Roberts, B. W., Avernue, K., and Askins, M. C., 1989, Remaining-Life Estimation of Boiler Pressure Parts, Volume 3: Base Metal Model, EPRI CS-5588, pp. 22–23.
3.
Shoji, T., 1964, Material Degradation & Life Prediction, REALIZE INC., pp. 179–186.
4.
Tanaka, C., 1990, NRIM Creep Data Sheet, No. 35A, NRIM, pp. 5–9.
5.
ASTM Standard, 1990, “Standard Practice for Production and Evaluation of Field Metallographic Replicas,” Annual Book, E1351-90, pp. 953–958.
6.
Vrhovac, M., Barata, J. C. R., and Rodrigues, R., 1996, “Automation of Microstructure Analysis by Artificial Intelligence Image Processing,” Proceedings of Failures ’96, pp. 297–312.
7.
Louis
,
P.
, and
Gokhale
,
A. M.
,
1995
, “
Application of Image Analysis for Characterization of Spatial Arrangements of Features in Microstructure
,”
Metall. Mater. Trans A
,
16
, pp.
1449
–
1456
.
Copyright © 2000
 by ASME
You do not currently have access to this content.