Nondestructive Evaluations of Structural Material with Residual Stress by Magnetic Tools

概要

論文の詳細を見る
The magnetic diagnosis of iron-based materials was performed by using many magnetic tools such as a small Hall element for leakage flux observations after polarizations, a locally sensitive fluxgate sensor available down to 100pT and by a pick-up coil for magnetic noise observation. The first derivatives of the normal components of the leakage flux with respect to positions along the applied tensile stresses were found reflecting the location of the heavily strained positions for ferromagnetic materials and inversely reflecting for the location of induced martensitic transformations for paramagnetic materials as SUS304. A numerical indicator of internal strains was derived by the magnetic noise measurements and the parameter well coincided with the degrees of strains and the directions of the strains observed by X-ray diffraction. These behaviors of magnetic inhomogeneity were visualized by the 2D display of the leakage flux by using the scanning of the magnetic sensor over the sample surface.
日本実験力学会の論文