The present study shows the relationship between welding quality and optical-acoustic emissions from electric arcs, during welding runs, in the GMAW-S process. Bead on plate welding tests was carried out with pre-set parameters chosen from manufacturing standards. During the welding runs interferences were induced on the welding path using paint, grease or gas faults. In each welding run arc vo...

A welding head is under development with integrated sensory systems for robotic laser welding applications. Robotic laser welding requires sensory systems that are capable to accurately guide the welding head over a seam in three-dimensional space and provide information about the welding process as well as the quality of the welding result. In this paper the focus is on seam tracking. It is di...

This study aims to calculate the resistance spot welding current digitally at a fast speed. The conventional open-loop spot welding machine cannot measure the current, thus the welding quality varies. The welding time of spot welder is very short, but the welding current is strong and it is hard to be measured, thereby resulting in the uncontrollability of welding quality. This study uses a hig...

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...

Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generat...

Spot welding is used extensively in the automotive industry. The quality of an individual welding spot is a major concern due to the heavy reliance on their use in the manufacture of cars. The main parameters that control the quality of a welding spot are current, voltage, welding force, welding time, and the quality of the welding electrodes. The condition of the welding electrodes plays a maj...

OBJECTIVES To study the airway response and its mechanism to welding fumes in six welders with respiratory symptoms. METHODS Methacholine and welding challenge tests were carried out. The concentration of welding fumes during the exposure test was measured. On two subjects who developed bronchoconstricition to welding challenge, additional tests were carried out including prick, patch, and in...