Residual stress measurements in a zircaloy-4 weld by neutron diffraction

The macroscopic stress distribution across a Zircaloy-4 gas tungsten arc weld was measured by time-of-flight neutron diffraction at the SMARTS diffractometer at Los Alamos National Laboratory. The method enabled the measurement of strain for all the available reflections permitted by the rolling texture of the plate and the modified texture in the weld-metal and heat affected zone. A maximum longitudinal stress of 220 ± 40 MPa was observed in the weld compared with the 0.2% yield stress of 390 MPa of the plate. A maximum transverse stress of 60 ± 40 MPa was observed in the weld. Textures were measured at the HIPPO diffractometer.