Residual Stresses in a Zircaloy-4 Weld

Abstract

The macroscopic stress distribution across a Zircaloy-4 (Zr-4) GTAW weld was measured by time-of-flight neutron diffraction at the SMARTS diffractometer at Los Alamos National Laboratory. Time-of-flight diffraction enabled the measurement of strain for all the available reflections permitted by the rolling texture of the plate and its modification in the weld (melted) and heat-affected zones. Reference lattice spacings were measured on coupons cut from an adjacent section of the weld. A maximum longitudinal stress of 220 ± 40 MPa was observed along the weld centre line, compared with the plate 0.2% proof stress of 390 MPa. A maximum transverse stress of 60 ± 40 MPa was observed on the weld centre-line falling to zero at the edge of the plate.