WEB Qualitative evaluation of the degree of local plastic deformation in bcc steels by means of electron backscatter diffraction (EBSD)Tuesday (22.09.2020) 11:50 - 12:05 Z: Special Symposia II Part of:
The degree of local pre-deformation is an important material characteristic which has influence on the operational mechanical as well as chemical properties. Localized plastic deformation plays an important role in the fatigue behavior of a material, since both geometrical discontinuities induced by the deformation process as well as microstructural changes (phase transformation, twinning a.o.) may act as crack initiation sites. Furthermore, the corrosion properties are strongly dependent on the plastic deformation . In order to better understand and prevent early component failure, it is essential to have detailed knowledge of the local degree of plastic deformation especially for more complex geometries and loads.
In particular, the determination of the degree of deformation for complex geometries such as clinch joints are difficult and cannot be determined without simulation. In this thesis the known plastic deformation of bcc steels is correlated with EBSD data to find a general relation to determine the degree of deformation in complex geometries for bcc steels without simulation.
Tensile tests under different strain conditions were performed and analyzed for a series of bcc steels to take an approach to determine the degree of local deformation. Electron back scattered diffraction (EBSD) investigations were carried out to analyze the different states of deformation. It was found that different degrees of local deformation have an influence on EBSD pattern quality as well as misorientation characteristics like the degree of the mean orientation spread. Subsequently a reshaped specimen with a practically orientated, unknown local deformations were analyzed and evaluated in regards to the before mentioned characteristics.
 GREENE, N. D., & SALTZMAN, G. A. (1964). Effect of Plastic Deformation On the Corrosion of Iron and Steel. CORROSION, 20(9), 293t–298t. doi:10.5006/0010-9312-20.9.293t