Composition dependence of the magnetomechanical effect and magnetostriction

Magnetomechanical and magnetostriction measurements were performed on a series of plain carbon steels, with carbon contents ranging from 0.1 to 0.9 wt.%. The microstructures in all specimens were similar, being a mixture of ferrite and pearlite, with the pearlite volume fraction increasing with increasing carbon. The magnetomechanical effect was found to vary with carbon content. Specifically, the change in magnetization with stress was proportional to the remanent magnetization for a given carbon level. Also, the sign of the magnetization change upon removal of compressive stress reversed at 0.6 wt.% carbon. The results were explained by the increased number of domain wall pinning sites produced by the increase in carbon content.