Stress Evaluation at the Maximum Strained State by EBSD and Several Residual Stress Measurements for Plastic Deformed Austenitic Stainless Steel

Abstract

This paper studies a method for obtaining the stress with plastic deformation by finding the plastic strain on U-bent specimens of austenitic stainless steel that have been subjected to large plastic deformation using the EBSD (Electron Backscatter Diffraction) method. The Mises stress calculated on the basis of the KAM of the EBSD shows good agreement with the stress that can be geometrically calculated from the U-bent specimens. In contrast, general methods for measuring residual stress on the basis of elastic strain produce residual stress measurement results that differ specimen by specimen. Thus, for true strain not less than 0.05, stress estimation based on the EBSD method produces better results than other general methods.

Process control maps to design an ultra-high strength-ductile steel

“…Figure 6(c) shows the grain boundaries of parent austenite grains and Figure 6(d) the inverse pole Figure of that austenite grain. Comparison between them shows that brighter parts of Figure 6(a) demonstrate lower stress level (blue parts) in Figure 6(b) which represent smaller distortion of tempered martensite [45]. In addition, although there are a few lathes of initial martensite in the structure, most of them are plate martensite and oriented along the grain boundaries of parent austenite grains (compare Figure 6(b,c)).…”

“…It is clear in this picture (Figure 5) that initial martensite (bright red) is formed mostly as plate martensite. Figure 6 [45]. In addition, although there are a few lathes of initial martensite in the structure, most of them are plate martensite and oriented along the grain boundaries of parent austenite grains (compare Figure 6(b,c)).…”

Evolution, Control, and Mitigation of Residual Stresses in Additively Manufactured Metallic Materials: A Review

“…[61][62][63] The Kikuchi patterns-based analysis of EBSD method enables the measurement of the stress variation by measuring the elastic strain, lattice rotation angle, and the geometrically necessary dislocation density. Sakakibara and Kubushiro [64] demonstrated that measurement of the kernal average misorientation through EBSD method can produce more accurate estimations of true Mises stress when the true strain is not less than 0.05. More recently, a novel characterization method, namely, Bragg edge neutron imaging method, was proposed by Morgano et al [65] With this method, it is assumed that the lattice strain can be more efficiently characterized when the spatial resolution of conventional nondestructive methods reaches the limit.…”

Evaluation of Deformation and Fracture Behavior in 304L Austenitic Steel Harmonic Structures through Nanoindentation

“…[21][22][23] Sakakibara and Kubushiro reported a linear relationship between the average KAM and measured true strain up to 0.18 in austenitic steel. [24] Therefore, the KAM maps in Figure 2c illustrate various local plastic strains. Confidence index (CI) lower than 0.1°was removed from the KAM maps.…”