Nonlinear Rayleigh waves to evaluate plasticity damage in X52 pipeline material

Abstract

This research uses nonlinear Rayleigh waves to examine different levels of plastic strain in samples made from legacy X52 pipeline material. Here the plastic strain is used as a surrogate for the damage associated with a pipeline dent. Tension specimens are subjected to a static, mechanical load. Nonlinear Rayleigh waves are used to measure the relative acoustic nonlinearity parameter, β′ in these specimens as a function of the accumulated plastic strain in the specimens. These results are then compared to previous β′ measurements made in A36 steel specimens, and a scenario based on the formation of dislocations is proposed to explain the increase in β′ observed. These measurements demonstrate the sensitivity of β′ to the microstructural changes caused by plastic deformation in X52 pipeline steel.