Quantification of plastic strain of stainless steel and nickel alloy by electron backscatter diffraction

Electron backscatter diffraction (EBSD) in conjunction with scanning electron microscopy is applied to assess the plastic strain present in stainless steel and nickel alloys following tensile loading. A parameter, which quantifies the spread of the crystal orientation within individual grains arising due to dislocation accumulation during plastic deformation, is correlated with imposed plastic strain. The parameter is called the ‘modified crystal deformation’ and is determined from the spread in misorientation from the central grain orientation. It was confirmed that the parameter has a good correlation to the degree of the plastic strain and is independent of the measurement conditions such as the EBSD system used for the measurement, number of data and step size in the crystal orientation map, electron beam condition, grain size and material.