RESIDUAL STRESSES ANALYSIS OF Nd-YAG LASER WELDED JOINTS

J.M. Costa  J.T.B. Pires  F. Antunes  J.P.Nobre  L.P. Borrego    

Anales de la Mecánica de la Fractura, nº 25 . 2008 . Pág. -
Ver (.pdf): 6-14

Resumen: Laser deposit welding based on modern ND-YAG lasers is a new mould repair process with advantages relatively to the traditional methods (Micro-plasma and TIG methods), namely deposition of small volumes of the filler material without distortion. Residual stresses play a major role on the fatigue and thermal-mechanical fatigue behaviour of welds. This paper presents the experimental results and numerical predictions of the residual stresses in joints manufactured with two hot-working tool steels: X.40.CrMoV.5.1 and 40.CrMnNiMo.8.6.4, in the laser-deposited layer and in the heataffected zone. Welded specimens were prepared with U notches and filled with Nd-YAG laser welding deposits. Trough-depth residual stresses evaluation after laser deposit welding were performed in order to analyse the influence of the residual stress state on fatigue behaviour of mould steels. Both X-ray diffraction sin2g method (XRD) and incremental hole-drilling technique (IHD) were used in residual stress measurement. Numerical predictions of the residual stress distributions were obtained for several values of the technologic parameters, compared with experimental results and discussed based on the assumptions stated.

LocalizaciónSigüenza

CEMUC, Department of Mechanical Engineering, University of Coimbra- Polo II, Pinhal de Marrocos, 3030-788, Coimbra, Portugal
Department of Mechanical Engineering, Polytechnic Institute of Castelo Branco, Avenida do Empresário, 6000-767 Castelo Branco
CEMUC, Department of Mechanical Engineering, University of Coimbra- Polo II, Pinhal de Marrocos, 3030-788, Coimbra, Portugal
CEMUC, Department of Mechanical Engineering, University of Coimbra- Polo II, Pinhal de Marrocos, 3030-788, Coimbra, Portugal
Department of Mechanical Engineering, Polytechnic Institute of Coimbra. Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra