In July 2015 Turbomecanica has enhanced the manufacturing capabilities with a high-tech 8D GTAW adaptive welding robot aiming to implement a program for reducing the weight of the GTAW manual welding for one of the most important manufacturing programs that consists of parts obtained from pressed stainless steel sheet of 3.2 mm thickness.
The difference between the 8D GTAW welding robotic compared to other similar applications is the fact that the welding line is not linear or circular, but it is of a free type S form. Furthermore, the geometry of the 2 halves which are welded leads to a variable dimension of the welding gap. The fact that the drawing is requiring GTAW welding and not for example GMAW welding is, adding a supplemental difficulty to the program.
In order to overcome these challenges, a laser scanner was used with the purpose to determine the position of the welding line and the welding gap dimension. The gap dimension is between 1.5 and 2.5 mm and for each interval of 0.1 mm gap, a certain set of welding parameters was established, this set being subsequently used by the robot in an adaptive mode.
After performing multiple tests both on coupons and on actual parts, the process was stabilized with the following benefits:
- reduction of the welding operation duration from 2 hours to 45 minutes, out of which 15 minutes robot welding and 30 minutes manual welding finishing on the interior of the part (62% reduction)
- reduction of argon gas consumption from 3.2 Nm3 to 1.8 Nm3 (44% reduction)
- improvement of the visual aspect and width of welding seam.
The program will continue with the introduction of robot welding for nickel alloy parts made from 4.8 mm thickness sheet.