鉄構・プラスチック加工のための中性子非破壊検査 I

－茨城県内の企業の話題から－

抄録

In order to promote the industry use of neutrons from inside Ibaraki prefecture, we initiated a collaboration with the union of steel welding in Ibaraki. By using a combined method of neutrons, i.e., radiography (NR), diffraction (ND) and small-angle scattering (SANS), which has recently developed on the iMATERIA instrument (BL20) at MLF in J-PARC, we examined the rod-shaped ferritic steel showing plastic deformation with necking after imposing large elongation of 20 % (the diameter decreases from 14 mm to 10mm, measured by a micrometer caliper). At a position of the necking, we found as follows, (i) near along a direction normal to the rod axis, the diffraction (110) increases 85 % in intensity and decreases 0.03 % in d-spacing (ii) the SANS intensity increases 300 % and (iii) the NR brightness increases 30 %. These findings are attributed to the reorientation of crystals and formation of microvoids under plastic deformation of ferritic steel.