Synchrotron measurements of local microstructure and residual strains in ductile cast iron

38th Risø International Symposium on Materials Science

Zhang, Y.B.^1 ; Andriollo, T.^2 ; Fæster, S.^1 ; Liu, W.^3 ; Sturlason, A.^4 ; Barabash, R.^5

Section for Materials Science and Advanced Characterization, Department of Wind Energy, Technical University of Denmark, Riso Campus, Roskilde

4000, Denmark^1

Department of Mechanical Engineering, Technical University of Denmark, Kgs. Lyngby

DK-2800, Denmark^2

Advanced Photon Source, Argonne National Laboratory, Argonne

IL

60439-4800, United States^3

Vestas Wind Systems A/S, Aarhus N

8200, Denmark^4

Materials Science and Technology Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge

TN

37831-6118, United States^5

关键词: Circumferential direction;    Dislocation boundaries;    Ductile cast irons;    Experimental characterization;    Finite element modelling;    Microstructural design;    Spherical graphite;    Synchrotron measurements;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/219/1/012054/pdf
DOI  :  10.1088/1757-899X/219/1/012054

来源: IOP

【 摘 要 】

The local microstructure and distribution of thermally induced residual strains in ferrite matrix grains around an individual spherical graphite nodule in ductile cast iron (DCI) were measured using a synchrotron X-ray micro-diffraction technique. It is found that the matrix grains are deformed, containing dislocations and dislocation boundaries. Each of the residual strain components in the matrix grains exhibits a complex pattern along the circumferential direction of the nodule. Along the radial direction of the nodule, strain gradients from the interface to the grain interior are seen for some strain components, but only in some matrix grains. The observed residual strain patterns have been analysed by finite element modelling, and a comparison between the simulation and experiments is given. The present study of local residual stress by both experimental characterization and simulation provide much needed information for understanding the mechanical properties of DCI, and represent an important contribution for the microstructural design of new DCI materials.