Feasibility of Residual Stress Nondestructive Estimation Using the Nonlinear Property of Critical Refraction Longitudinal Wave

Figure 10

Microstructures of grade 45 steel specimens when the prestress is (a) 100 MPa, (b) 200 MPa, (c) 300 MPa, and (d) 400 MPa.

(a)

(b)

(c)

(d)