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

Yohei Sakakibara,Keiji Kubushiro

doi:10.4236/wjm.2017.78018

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.

Highlights

The methods that have been used for evaluating residual stress on structures include the X-ray diffraction method [1], the Sectioning method [2], and the center hole drilling methods (CHD) and deep hole drilling (DHD) [3]
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 EBSD method is only applicable to the stress with the maximum strained state of specimens and cannot be used for estimating the residual stress with bolts to maintain the bent state loosened as was the case for the U-bent specimens this time

Summary

Introduction

The methods that have been used for evaluating residual stress on structures include the X-ray diffraction method [1], the Sectioning method [2], and the center hole drilling methods (CHD) and deep hole drilling (DHD) [3] These methods have been used for deliberations on manufacturing methods. This method compares the Kikuchi pattern of specific measurement points with other measurements for the same crystal grains in the same samples, and it can only be used for the estimation of elastic strain and stress relative to reference points remaining in the samples. The method cannot be used to obtain absolute values of elastic stress because elastic strain is mostly released when samples are taken out of structures

Methods

Results

Discussion

Conclusion