Detection of plastic deformation gradients in steel using scanning SQUID microscopy

Scanning SQUID microscopy is shown to be capable of detecting deformation g radients when accompanied by significant changes in hardness, Deformation w hich does not increase the dislocation density las measured by the increase in hardness) has little effect. The effect can be produced by different te chniques including cold rolling and tensile deformation, The effect is show n to occur in at least two different alloys with very different microstruct ures indicating the possibility of wide applicability.