Soldabilidade por centelhamento do aço Dual Phase 780

• Ano de defesa: 2013
• Autor(a) principal: Nissandro Domingues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Laminação a frio; Aço dual phase; Soldagem por centelhamento; Engenharia metalúrgica; Laminação (Metalurgia); Metalurgia de transformação
• Link de acesso: http://hdl.handle.net/1843/BUOS-9B9JCJ

This work evaluates the flash-butt weldability of hot rolled strip of dual phase 780 steel with ferrite-pearlite microstructure. The influence of the following welding parameters on the microstructure, mechanical properties and performance of the welded joints during cold rolling and continuous annealing processing was investigated: Voltage application time, 2nd stage flash voltage, upset length, initial lenght, upset electric current time and post-heating time. Under the conditions studied, changes in welding parameters modify the microstructure, hardness and the length of HAZ, and the initial length and the post-heating time were the parameters that caused more changes in these characteristics. The performance of the joints, in turn, is highly dependent on the amount of oxides trapped in the weld line and was greatly influenced by acceleration of the welding machine movable table. None of the welding conditions evaluated, however, resulted in joints free of cracks in the weld line after cold rolling.