Effect Of Welding Current On Hardness Of Heat Affected Zone İn Shielded Metal Arc Welding Process Using Different Electrodes
Abstract
Several structural members require hardness with joints. Heat affected zone changes its microstrure, hence its mechanical properties are changed. The required value of hardness should not be more than the hardness of the material. The shielded metal arc welding process is a popular arc welding process. In the present work the investigation of the effect of three different types of electrodes at three different welding currents in shielded metal arc welding process utilizing Low Carbon Steel plate of API 5L Grade X 52, was done for hardness of the heat affected zone. The three different electrodes as E 6013, E 7016 and E 7018 and the varying currents as 90 A, 100 A and 110 A were used. Total 18 pieces were used to obtain 9 different welds which were used to analyze the effect of current and the electrode on hardness of the heat affected zone. The dimensions of the work pieces were taken as 75 mm x 50 mm x 5 mm. The hardness values in each heat affected zone were written in a table and respective diagrams were drawn to make clear the effect of welding current on hardness of heat affected zone for the three different electrodes. It was found that hardness of the heat affected zone decreased with increase of current for all the three types of electrodes