TY - JOUR AU - Martínez, A. AU - Miguel, V. AU - Coello, J. AU - Navarro, A. AU - Calatayud, A. AU - Manjabacas, M. C. PY - 2011/02/28 Y2 - 2024/03/28 TI - Analisys of the influence of the multipass welding, welding pre heat and welding post heat treatments on the behaviour of GMAW joints of HARDOX 400 microalloyed steel JF - Revista de Metalurgia JA - Rev. metal. VL - 47 IS - 1 SE - Articles DO - 10.3989/revmetalmadrid.1007 UR - https://revistademetalurgia.revistas.csic.es/index.php/revistademetalurgia/article/view/1179 SP - 61-75 AB - The microalloyed steels may be supplied in a hardened state. In these cases, the weldability can be improved by pre-heat and/or post-heat welding treatments. In this paper, the effect of those treatments and the influence of multipass welding on GMAW joints behavior are analyzed for a Hardox 400 microalloyed steel. The microstructure evaluation of the different heat affected zones of the steel has been made and the mechanical properties of those zones are obtained for different conditions as it has been mentioned. The obtained results indicate that preheating the steel leads to a beneficial action that consists on the distance increasing from the bead to the zone in which the hardness is lowest. The postheat treatment strengthens that zone and improves the joint plasticity. This benefit is higher if the joint has been made with preheating. Multipass welding has not been found to have any advantage if it is compared to a single welding pass. ER -