Application of neutron stress measurement method without stress-free lattice constant to practical material

Suzuki, Hiroshi  ; Moriai, Atsushi; Minakawa, Nobuaki*; Morii, Yukio

In a conventional method of a neutron stress measurement, it is required to know the stress-free lattice constant accurately. A new stress measurement method, which does not need the lattice constant of the strain-free material, was applied to evaluate the residual stress distributions in welded sample. The lattice constant distribution which was measured by using our proposed method showed an increase as close to the weld zone, and the absolute value of the lattice constant almost agreed with the lattice constant which was measured using coupons cut from welded sample. Therefore, it is possible to predict the lattice constant by using our proposed method. The residual stress distributions were evaluated by using conventional method and our proposed method. As a result, the residual stress distributions decided by our proposed method almost agreed with those measured by conventional method. This proposed method can be applied to determination of the residual stress states in the samples with the complex residual stress states.