Installation of new pipelines is predicted to grow at a rapid rate over the next twenty years, due in part to the increase use worldwide of combined cycle power generation plant using natural gas a fuel. The need to construct large diameter pipelines over long distances has led to an increased demand to improve the productivity of pipeline girth welding. Many novel techniques have been tried in...

This paper concentrates on the microstructural analysis of the three-dimensional (3D) parts built by rapid prototyping (RP) based on gas tungsten arc welding (GTAW). The material used for building 3D parts is AISI 1018. Two sets of experiments are carried out. From each experiment, samples are obtained by a standard metallographical procedure: cross sectioning, polishing, and etching. During th...

GAS TUNGSTEN ARC WELDING (GTAW) is the quality weld process. It is preferred welding process for stainless steel, low alloy steel, nickel, cobalt, titanium, aluminum, copper, and magnesium. The present work aims to evaluate the effect of Gas Tungsten Arc Welding process parameters on the quality of the weld bead. The process parameters Welding Current, Wire Diameter, Wire Feed Speed, Ratio of w...

Due to lack of comprehensive experimental studies on welding processes, and to better understand the mechanisms behind these processes, especially the weld pool shape variations suspected due to Marangoni Effect or surface tension shear stress, a two-dimensional simulation model was developed to study the physics of gas tungsten arc welding (GTAW). Experimental spot-welds on Ti-5Al-5Mo-5V-3Cr w...

This study proposes a method for determining the near-optimal settings of welding process parameters using a controlled random search (CRS) wherein the near-optimal settings of the welding process parameters are determined through experiments. The method suggested in this study is used to determine the welding process parameters by which the desired weld bead geometry is formed in gas metal arc...

Gas metal arc welding (GMAW) is the most widely used process for metal joining because of its high productivity and good quality, but analysis shows that the fundamental characteristic restricts conventional GMAW from further increasing the welding productivity. A novel GMAW process, refereed to as double-electrode GMAW or DE-GMAW, thus has been developed to make it possible to increase the mel...

Welding is an important manufacturing process that can be automated and optimized. This paper focuses on the development of a robotic arc welding system, wherein a three-degreeof-freedom Selective Compliance Assembly Robot Arm (SCARA) is interfaced to a Gas Metal Arc Welding (GMAW) process. The entire system is composed of a robot linked to a GMAW system. Set points are derived using the desire...

The weld pool is the core of the welding process where complex welding phenomena originate. Skilled welders acquire their process feedback primarily from the weld pool. Observation and measurement of the three-dimensional weld pool surface thus play a fundamental role in understanding and future control of complex welding processes. To this end, a laser line is projected onto the weld pool surf...

This paper deals with weld pool oscillation during pulsed gas tungsten arc (GTA) welding of unalloyed steel. Experiments were carried out in which the weld pool was triggered into oscillation during both the base time and the pulse time by short current peaks, superimposed on the pulsed welding current. The arc voltage was continuously measured during welding and the oscillation frequency spect...