STRUCTURAL STUDIES OF BEARING STEEL UNDERGOING CYCLIC STRESSING.
Abstract
Accumulations of plastic strain, visible in the light microscope as white etching deformation bands, are shown to develop in bearing steels undergoing cyclic stressing. Under the electron transmission microscope the deformation bands appear as cell like structures circled by tangled dislocation loops and devoid of temper carbides. Two conditions are found to initiate the growth of deformation bands: (1) localized plastic yielding around imperfections; (2) plastic yielding of some volumes of the bulk material under the influence of the maximum shear stress when it exceeds a critical threshold level, estimated to be 120,000 psi. Deformation bands are shown to be involved in the propagation of fatigue cracks and are associated with the early stages of fatigue cracking initiated by two types of imperfections: surface furrows and non-metallic inclusions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 29, 1966
- Accession Number
- AD0482893
Entities
People
- A. D. Eberhardt
- J. A. Martin
- S. F. Borgese
- W. Berlinghof