抄録
The Magnetic diagnosis of iron-based materials is performed by using a small Hall element for the leakage flux observation after polarizations of these materials. We found first derivatives of the normal component of the leakage flux along with the positions well coincided with intensities of residual strains for samples of SUS304,A533B and S25c, where the intensities of the first derivative in reversed proportional for paramagnetic amterial of SUS304 due to induced martensitic transformations and positively proportional for ferromagnetic materials of A533B and S25C.
