Abstract
The objective of this work was to evaluate the mechanical properties of weld metals of different coated electrodes, class AWS E309 (309L-15, 309L-16, 309MoL-15 and 309MoL-16) from three manufacturers available in the national market. The welds were conducted in the flat position on 1020 ABNT steel plates milled and buttered in accordance with AWS standard A5.4-06. Test pieces were removed for chemical analysis, metallographic analysis and tensile resistance testing. The test pieces were removed from the welds and the tests were also carried out in accordance with the appropriate standards. The results indicate that the level and the morphology of the δ-ferrite has a significant influence on the tensile resistance and ductility of the weld metal, and in some cases they do not comply with the requisites of the AWS standard A5.4-06 in regard to ductility. The conclusion is that electrodes manufactured to the same standard have significant differences in δ-ferrite values, tensile resistance and ductility, which resulted in significant differences in the mechanical properties of the weld metal.
Acknowledgements
The authors would like to thank Eng. Mário Castro, of EB-IME and Professor M.Sc. Willys Machado Aguiar (CEFET-Ce) for their contribution to the research, LAPROSOLDA-UFU for the measurement of δ-ferrite, Acesita S/A for the chemical analyses and Petrobras/Lubnor for producing the welds. They would also like to thank ANP/PRH-31, CAPES and the CNPq for their financial support, and ENGESOLDA-UFC, LACAM-UFC and LEM-CEFET-CE laboratories for the infrastructure that was indispensable in carrying out this work.