Abstract:
The ship and building industry in Thailand has been improved through the use of aluminum. Since it has the characteristic of lightness and durability,
it has proven to make work fast and effective. Ship building using the process of welding side by side consumes more time. In this study, a new process was developed
and called as Gas Metal Arc Welding (GMAW). Double sided arc welding are more effective and efficient because it decreases working time and procedure. We have
found out that we only have to choose the proper parameters to have a perfect welding process. By setting the parameters of two torches at arc voltage 19.5 volts, current
132 amp, wire feed speed 8.4 millimeters, penetration 3.0 millimeters. All weld parameters were set to be the same for all experiment except that the offset distances were
varied by setting at 0, 5, 10, 15, 20, 25 millimeters.
After the procedure, the materials are checked then undergoes visual, Bend and Hardness tests. So as to pass the ANSI/AWS D1.2-90 standard. This study has found out
that there are different penetration depending on two torch distances. The areas of most weldment penetration were 0, 5, 10 milimeters and the areas with the least weldment
penetration were 15, 20, 25 millimeters. There were different penetration that depend on two torch distances , resulting in different hardness.
Furthermore the last of this thesis have been welded through this process using aluminum grade 5083, with thickness of 10 millimeters at the same as thickness of 6 millimeters.
Using only the most proper parameters and off-set distance stable at 0 millimeter. After welding it was found that, in the area of non weldment penetration, the result showed
the diffusion of aluminum cannot penetrate well as showed in both mechanical and microstructure examination.