S18  Processos Mecânico-Metalúrgicos    Titulo: DETERMINATION OFTHE MELTING RATE OF COVERED ELECTRODE FOR WELDING WITH AN INDUSTRIAL ROBOT IR2000   Resumo : DETERMINATION OF THE MELTING RATE OF COVERED ELECTRODE FOR WELDING WITH AN INDUSTRIAL ROBOT IRB2000 ABSTRACT. DIFFERENTLY TO THE WELDING PROCESSES MIG, MAG, AND FCAW, THE MECHANIZATION AND THE ROBOTIZATION OF THE SHIELDED METAL ARC WELDING PROCESS (SMAW) HAVE BEEN HINDERED BY INTERRUPTIONS OF THE WELDING OPERATION FOR ELECTRODE CHANGE, THAT REDUCES THE PRODUCTIVITY, AND MAKE DIFFICULT THE EXECUTION OF GREAT LENGTH WELDS. THAT IS WHY THIS PROCESS IS STILL CONSIDERED AS A MANUAL ONE. HOWEVER, EVEN WITH EFFICIENT DEVICE OF ELECTRODE CHANGE, THE HEATING OF THE SAME, FOR CURRENTS ABOVE 100A, PROVOKES CHANGES IN ITS MELTING RATE, THAT CAUSE VARIATIONS OF THE ELECTRIC ARC LENGTH, RESPONSIBLE FOR THE UNDESIRABLE QUALITY OF THE WELDS. IN THIS WORK, THE MELTING RATE OF COVERED ELECTRODE WAS MEASURED RELATIVE TO THE WELDING TIME, AND THIS WAS ASSUMED AS DOWNWARD FEEDING SPEED OF THE ELECTRODE HOLDER IN THE ROBOT S PROGRAM. EXPERIMENTAL TESTS OF WELDING WITH ROBOT SHOWED THAT FOR CURRENTS ABOVE 100A, IF THE FEEDING SPEED OF THE ELECTRODE DURING WELDING GOES CONSTANT, THE PROBABLE RESULT IS A WELD WITH BAD QUALITY. HOWEVER, WHEN ASSUMING THE FEEDING SPEED OF THE ELECTRODE EQUAL TO THE MELTING RATE, THE ROBOT GETS TO COMPENSATE THE CONSUMPTION OF THE ELECTRODE, MAINTAINING THE ELECTRIC ARC LENGTH CONSTANT, THAT RESULTS IN WELDS WITH ACCEPTABLE QUALITY. KEY-WORDS: HEATING OF THE ELECTRODE, MELTING RATE, FEEDING SPEED.     Autores : Absi-Alfaro, Sadek C. Batana, Jean Robert Bracarense, Alexandre Queiroz     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local