Abstract :
Welding that is often used in the construction world in general is
welding using welding methods with a shielded metal flame arc or commonly
called Shielded Metal Art Welding (SMAW). The SMAW method is widely used at
this time because its use is more practical, easier to operate, can be used for all
kinds of welding positions and is more efficient. This research was conducted to
determine the mechanical properties of ST40 steel, where the welding process
uses a current variation of 80A, 100A, 120A with E6018 electrode with a diameter
of 2.6 mm, V angle of 60º. Based on the results of the study obtained the highest
tensile strength with a current of 80A of 340.87 N / mm2 and the lowest tensile
strength at a current of 120A of 330.48 N / mm2. The highest value of violence is
found in the current 100A with the average value of each region; the weld is 49.7
kg / mm2, HAZ is 51 kg / mm2, and base metal is 49 kg / mm2. The lowest
hardness value is in the current 120A with the average value of each region;
welds of 48.8 kg / mm2, HAZ of 49.7 kg / mm2, and base metal of 49.5 kg / mm2.