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Deformation, Recovery and Stress Corrosion Cracking of Nickel-Base Alloy 600 by X-ray Rocking-Curve Measurements

Published online by Cambridge University Press:  06 March 2019

Chi Fung Lo ,
Gajiang Feng ,
William E. Mayo  and
Sigmund Weissmann
Chi Fung Lo
Affiliation:
Department of Mechanics and Materials Science, Rutgers University, P.O. Box 909, Piscataway, NJ 08855-0909
Gajiang Feng
Affiliation:
Department of Mechanics and Materials Science, Rutgers University, P.O. Box 909, Piscataway, NJ 08855-0909
William E. Mayo
Affiliation:
Department of Mechanics and Materials Science, Rutgers University, P.O. Box 909, Piscataway, NJ 08855-0909
Sigmund Weissmann
Affiliation:
Department of Mechanics and Materials Science, Rutgers University, P.O. Box 909, Piscataway, NJ 08855-0909
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Abstract

The aim of this investigation was the establishment of a quantitative link between micro and macrodeformation and kinetic recovery of nickel-base Alloy 600 as well as the early detection of microcracks in this alloy when exposed to stress corrosion. To reach these objectives, X-ray rocking-curve measurements were carried out using the method known by its acronym CARCA (computer-aided rocking-curve analysis). Supported by transmission electron microscopy, a calibration curve was established relating dislocation density, X-ray rocking-curve halfwidth and strain. Applying CARCA, deformation levels and work-hardening characteristics of the alloys were measured by quantitative characterization of the induced defect structure. By correlating the analysis of the defect structure to the kinetic recovery of the alloys, including determination of the activation energies, it was possible to infer from the thermal stability of the alloys the dislocation obstacles responsible for hardening at different strain levels. It was shown that the recovery of the alloys was conditioned by their low stackingfault energy and that it depended on the strain level. Rapid recovery associated with grain boundary diffusion occurred at very small plastic strains up to about 0.7% with measured activation energies of recovery of about 25.6 Kcal/mol. At higher strains bulk diffusion was necessary to overcome the obstacles by dislocation climb with Q — 67 kcal/mol, The CARCA method proved itself to be a valuable research tool for assessing quantitatively the defect density and the mechanically and thermally induced changes. Relaxation effects, recorded by CARCA in the apex region of stressed C-rings exposed to a caustic medium, may open a path for early nondestructive detection of microcracks in stress-corrosion cracking.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 33: Thirty-Eighth Annual Conference on Applications of X-ray Analysis, July 31 - August 4, 1989 , 1989 , pp. 33 - 53
Copyright
Copyright © International Centre for Diffraction Data 1989

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References

[1] Kalman, Z. H. and Weissmann, S., Determination of Strain Distribution in Elastically Bent Materials by X-ray Intensity Measurements, J. Appl. Crystallogr. 12: 209 (1979).Google Scholar
[2] Kalman, Z. H., Chaudhuri, J., Weng, G. J. and Weissmann, S., Determination of Strain Concentration by Microfluorescent Densitometry of X-ray Topography: A Bridge Between Microfracture and Continuum Mechanics, J. Appl. Crystallogr., 13: 290 (1980).Google Scholar
[3] Chaudhuri, J., Kalman, Z. H., Weng, G. J. and Weissmann, S., Determination of the Strain Concentration Factors Around Holes and Inclusions in Crystals by X-ray Topography, J. Appl. Crystallogr. 15: 423 (1982).Google Scholar
[4] Liu, H. Y., Weng, G. J. and Weissmann, S., Determination of Notch-lip Plasticity by X-ray Diffraction and Comparison to Continuum Mechanics, J. Appl. Crystallogr. 15: 594 (1982).Google Scholar
[5] Liu, H. Y., Mayo, W. E. and Weissmann, S., MApplng and Analysis of Microplasticity in Tensile-Deformed Double-Notched Silicon Crystals by Computer-Aided X-ray Double-Crystal Diffractometry, Mat. Sci. and Eng., 63: 81 (1984).Google Scholar
[6] Mayo, W. E. and Weissmann, S., Nondestructive Failure Prediction in Cycled Commercial Alloys by CARCA, in: “Fatigue-84”, Beevers, C. J., ed., Eng. Mat. Advisory Serv. Ltd., Birmingham (1984).Google Scholar
[7] Weissmann, S., X-ray Failure Prediction Based on Plasticity Response to Mictocrack, in: “Fatigue-87”, 3: 1459, Emas Eng. Mat. Advisory Serv. Ltd., Birmingham (1987).Google Scholar
[8] Lo, C. F., H. Kainide, Feng, G. F., Mayo, W. E. and Weissmann, S., X-ray Determination of Stress-Strain Distribution in Unnotched C-rings: A Link from Micro- to Macromechanics, Acta. Metall. 36: 3069 (1988).Google Scholar
[9] Van Rooyen, D., Review of the Stress Corrosion Cracking of Inconel 600. Corrosion J. 31: 327 (1975).Google Scholar
[10] Lee, D. and Vermilyea, D. A., The Initiation of Intergranular Failure in Inconel 600, Metall. Trans. 2: 2565 (1971).Google Scholar
[11] Blanches, C. L., Corion, H., Grail, L., Mathieu, C., Otter, C. and Turluer, G., Influence de la contrainte, des traitments thermiques et des couplaques sur la fissuration intergranulaire des alliages Inconel 600 et X750, J. Nucl. Mater. 55: 187 (1975).Google Scholar
[12] Eriant, C. L. and Banerji, S., Intergranular Failure in Steel: The Role of Grain Boundary Composition, Int. Metall. Ray. 23: 164 (1978).Google Scholar
[13] Yazici, R., Mayo, W. E., Takemoto, T. and Weissmann, S., Defect Structure Analysis of Polycrystalline Materials by Computer-Aided Diffractometer with Position-Sensitive Detector, J. Appl. Cryst. 16: 89 (1983).Google Scholar
[14] Smith, C. S. and Guttmann, L., Measurement of Internal Boundaries in Three-Dimensional Structures by Random Sectioning, Trans. AIME. 197: 81 (1953).Google Scholar
[15] Bruemmer, S. M. and Henager, C. H., High Voltage Electron Microscopy Observations of Microdeformation in Alloy 600 Tubing, Scr. Metall., 20: 909 (1986).Google Scholar
[16] Bruemmer, S. M., Charlot, L. A. and Henager, C. H., Microstructure and Microdeformation Effects on IGSCC of Alloy 600 Steam GeneratorGoogle Scholar
[17] Johnson, W. A. and Mehl, R. F., Reaction Kinetics in Processes of Nucleation and Growth, Metals Technology 6: 5 (1939).Google Scholar
[18] Avrami, M., Kinetics of Phase Change I - General Theory, J. Chem. Phys. 7: 1103 (1939).Google Scholar
[19] Smidoda, K., Gottschalk, C. and Gleiter, H., Grain-Boundary Diffusion in Migrating Boundaries, Met. Sci. 13: 146 (1979).Google Scholar
[20] Kuhlntan-Wilsdorf, D., Theory of Plastic Deformation, Properties of Low-Energy Dislocation Structures, (Penny Lectures) Int. Conf. on Low Energy Dislocation Structures. University of Virginia, Charlottesville, VA (1989).Google Scholar
[21] Ashby, M. F., The Deformation of Plastically Non-Homogeneous Material, Phil. Mag. 21: 399 (1970).Google Scholar
[22] Wilsdorf, H. G. F., The Ductile Fracture of Metals; A Microstructure Viewpoint, Mat. Sci and Eng. 59: 1 (1983).Google Scholar
[23] Jagannadham, K. and Wilsdorf, H. G. F., Low Energy Dislocation Structures Associated with Cracks in Ductile Fracture, Mat. Sci. and Eng. 81: 283 (1986).Google Scholar