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  • Influence of Microstructure and Strain Hardening Rate on Acoustic Nonlinearity Parameter in Stainless Steel 316L during Tensile Loading
Title: Influence of Microstructure and Strain Hardening Rate on Acoustic Nonlinearity Parameter in Stainless Steel 316L during Tensile Loading
The accumulation of dislocations, which are atomic defects in materials subjected to plastic deformation, can cause structural failures. Early detection of such dislocation-related damage is essential to prevent these failures. The acoustic nonlinearity parameter β has been shown to be sensitive to the nonlinearity of dislocation motions, and prior research has shown a relationship between β and dislocation parameters in various damage mechanisms. While most work thus far reports that β generally increases with increased plastic deformation, recent research showed that β can decrease during monotonic tensile loading in stainless steel 316L characterized by in situ nonlinear ultrasonic measurements. The objective of this research is to examine the correlation between the decrease of β with plastic strain as reported in this recent study, and the initial microstructure and strain hardening rate. The initial microstructure, characterized with electron backscatter diffraction (EBSD), shows an increase in dislocation density and a reduction of grain area, which can possibly result in a decrease in β. Further, it is shown that the decrease rate of β monotonically decreases with hardening rate, providing a evidence that the decrease in β may relate to the shift from planar slip to wavy slip. These results help interpret the underlying mechanisms for the decrease in β during tensile loading.  more » « less
Award ID(s):
2015599
PAR ID:
10532018
Author(s) / Creator(s):
; ;
Corporate Creator(s):
;
Publisher / Repository:
The American Society for Nondestructive Testing Inc.
Date Published:
ISBN:
9781571175960
Subject(s) / Keyword(s):
Nonlinear ultrasound, Rayleigh wave, Acoustic nonlinearity parameter, EBSD, Grain Area, Kernel Average Misorientation, Strain hardening rate, Plastic deformation, In situ measurements
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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