Abstract:
The AWS A5.1 E6013 electrodes have great interest due to their wide employability. The coatings of these electrodes can alter the results of welding, making it an interesting object of study. An investigation of the chemical composition of the coatings of the electrodes AWS A5.1 E6013 from four Brazilian manufacturers was carried out using dispersive energy X-ray fluorescence spectrometry (DEXRF), scanning electron microscopy (SEM), and mass spectrometry with inductively coupled plasma (ICP-MS). Compounds such as titanium dioxide (TiO2), alkali and alkaline earth metal oxides, and carbonates were observed in the samples, in addition to Al and Si in the form of aluminosilicates. These compounds assist in the extrusion of the coating at the electrode manufacturing stage, increase the basicity of the slag and stabilize the electrical arc formed during welding. The results of the ICP-MS showed that elements such as Co, Cr, Cu, and Ni are added to increase the passivity and the mechanical resistance of the welded joint. Pb residues were observed with levels up to 700 times greater than allowed by national legislation. The presence of these metals in the coatings evidences the need for protective measures when handling the E6013 electrodes.
Key-words:
Coated electrodes; AWS A5.1 E6013; Chemical composition; X-ray fluorescence; ICP-MS