Nonlinear ultrasonic characterization of thermal degradation in ferritic 2.25Cr–1Mo steel

Prediction of the Mechanical Properties of P91 Steel by Means of Magneto-acoustic Emission and Acoustic Birefringence

“…Mutual relationships between parameters of ultrasonic waves and creep damage were observed [13,14]. Variations of nonlinear acoustic parameters were investigated in the course of creep [15]. In late creep stages, when numerous voids have been created in the bulk steel specimens, an ultrasonic technique based on acoustic birefringence was used to detect material damage [16].…”

Creep degradation characterization of titanium alloy using nonlinear ultrasonic technique

“…The strain field resulting from the precipitate-matrix lattice misfit may increase the stress, which can be given by σ % 2μεf p [30], where f p is the volume fraction of the dispersed precipitate phase and ε is the coherency strain. For assuming the precipitates to be spherical and elastically isotropic, the coherency strain resulting from a spherical precipitate embedded in a finite matrix is presented as ε ¼ 3Kδ=3K þ 2Eð1 þ νÞ, where K is the bulk modulus of the precipitate, and E and ν are the Young's modulus and Poisson's ratio in the matrix.…”

Creep Characterization in Advanced Heat-Resistant Steel Using Ultrasonic Nonlinearity Technique

“…The nonlinear stressstrain (·¾) relation can be expressed up to secondorder term, · = E¾(1 + ¢¾ + +), for the simple one-dimensional case where E is second-order elastic constant and ¢ is second-order nonlinear coefficient. If we consider the one dimensional wave propagation of a pure longitudinal wave in a lossless solid, the nonlinear wave equation and its solution can be obtain by perturbation process as follows: 20) uðx; tÞ ¼ A cosðkx À ½tÞ þ A 2 k 2 ¢x…”