Strain localizations during cyclic deformation investigated by high-resolution digital image correlationWednesday (26.09.2018) 14:30 - 15:00 S1/01 - A02 Part of:
Different types of strain localizations are observed under static, dynamic and cyclic loading of metallic materials. During cyclic deformation, the strain is localized within so-called slip bands, persistent slip bands or deformation bands. In metastable austenitic stainless steels, the later one consists of densely arranged stacking faults and are favored places for martensitic phase transformation. The high-resolution digital image correlation (DIC) in combination with scanning electron microscopy (SEM) is a powerful method for determination of the localized strains within deformation bands caused by stacking faults and alpha’-martensite . In situ cyclic loading experiments on a metastable high-alloy CrMnNi cast steel were performed in SEM at room temperature. The DIC was used on SEM micrographs of etched specimen surface to evaluate local strain fields in the microstructure developing in dependence on the applied number of cycles. The area of interest was analyzed after the cyclic loading test (N=1500) by electron backscattered-diffraction (EBSD) in order to characterize the developed microstructure. Detailed variant analysis of the alpha’-martensite in combination with analysis of operating slip systems allowed for an interpretation of the complex local strain fields occurring within deformation bands during cyclic deformation.
 A. Weidner, C. Segel, H. Biermann: Magnitude of shear of deformation-induced ’-martensite in high-alloy metastable steel, Mater. Lett. 143 (2015) 155-158.