Resumen en inglés

In this monograph, the effect that the heat input generated by fusion welding processes in high-strength and low-alloy steels has been studied on the microstructure and on the fracture toughness and impact resistance. A bibliographic review including articles, research works and scientific reports was carried out where these steels were welded with different processes and / or the thermal cycles suffered by a welded joint were simulated through thermal treatments and software that recreated these conditions. Afterwards, by means of optical microscopy tests, scanning electron microscopy, hardness and microhardness tests, Charpy impact resistance tests and CTOD fracture toughness tests, among other techniques the steels were characterized and evaluated on the welded zones and sub-zones, in especially the heat affected zone of the base metal, where the greatest variation of microconstituents was concentrated. According to the results, it was determined that the toughness and the fracture behavior are subject to microstructural changes due to the heat input from the welding processes