Influência de parâmetros de soldagem dos eletrodos E 10 UM 60 G e E 10 UM 65 G

Abstract

This work aims to evaluate the effect of the welding parameters of the electrodes E 10 UM 60 G and E 10 UM 65 G in the hard coating process and contribute to the development and efficiency of this technique. For this purpose, the welding process had two parameters of control voltage and welding speed in a low hardness plate (ASTM 36) in order to evaluate the most relevant parameters and how the parameters affected the weld geometry. Thereafter, SMAW process was done on sheet metal of ASTM 36, the coating was being made with 50% dilution of the above weld bead and a coating layer made. For this step, the tension was fixed and only the welding speed was changed in two speed velocity parameters and consequently with two different heat inputs. After the final welding step, the samples were cut and analyzed for the geometric profile, rockwell hardness and microstructure. The electrodes had different behaviors in relation to hardness, geometric profile and microstructure. The E 10 UM 60 electrode showed higher deposition rates causing lower dilution, higher reinforcement and greater width than the electrode E 10 UM 65 G. The electrode E 10 UM 60 G did not have significant differences in relation to the hardness due to the energy change of welding, while the electrode E 10 UM 65 G had differences in hardness with the same change in heat input. The same was observed, in the microstructure, since the electrode E 10 UM 60 G had few significant alterations such as increase of the carbides and less formation of cracks due to greater welding energy, while the electrode E 10 UM 65 G showed a dendritic structure with little precipitation for low welding energy and a structure with more precipitates in a homogeneous matrix using high welding energy.