Overlay welding of nickel alloys for corrosive and sour service is commercially accomplished with most welding processes ranging from shielded metal arc (stick) to laser. The valve industry has generally standardized on hot wire gas tungsten arc (GTA-HW), pulsed gas metal arc (GMA-P) and submerged arc (SAW) welding. This document will focus on these three but a little history will help explain ...

We investigated relationships between occupational exposure to gas and arc welding fumes and the risk of lung cancer among workers exposed to these agents throughout the spectrum of industries. Two population-based case-control studies were conducted in Montreal. Study I (1979-1986) included 857 cases and 1066 controls, and Study II (1996-2001) comprised 736 cases and 894 controls. Detailed job...

The development and fabrication of fusion reactor components utilize different grades of stainless steel materials and different welding techniques. Major candidates are TIG welding, Laser welding and Electron beam welding and Narrow Gap TIG welding. The weld joints quality evaluation and their mechanical properties are to be analyzed for performance of these developed components. The welded jo...

This paper describes the relationships between ultra-violet emission, ozone generation and CrVI production in MIG welding which were measured as a function of shield gas flow rate, welding voltage, electrode stick-out and shield gas composition using an automatic welding rig that permitted MIG welding under reproducible conditions. The experimental results are interpreted in terms of the physic...

This paper develops an automatic welding control scheme for alternating current shielded metal arc welding (SMAW) system. A mathematical model of the welding control system is derived and the system parameters identified. An adaptive sliding mode controller is designed to estimate the bound of the system uncertainties and to modulate the electrode feed rate in such a way that the desired arc le...

Using robots with industrial welding operations is common, but far from being a solved technological process. The problems are with the robots, still in early stages, difficult to use and program by regular operators; the welding process, complex and not really well known; and the Human-Machine interfaces, non-natural, really not working. In this paper these problems are discussed and is presen...

Industrial requirements concerning the increased efficiency and high rate of manufacturing result in the development of manufacturer robots, and a vast group of these types of robots is used for welding. This study presented the design, analysis, and simulation of a pipe-welding robot with fixed plinth for a constant circular welding around the pipes. Design of a welding robot capable of keepin...

The information system is a coherently structured assembly, made of electronic computing and communication equipments, software, processes, automated and manual procedures, used as automatic data processing tool within a field of activity. In the process of welding in shielding gas environment with fusible electrode, there are used either inert or active gases. Therefore, we make the distinctio...

Resistance spot welding process comprises of electric, thermal and mechanical phenomenon, which makes this process complex and highly non-linear and thus, it becomes difficult to model it. In order to obtain good weld nugget during spot welding, hit and trial welds are usually done which is very costly. Therefore the numerical simulation research has been conducted to understand the whole proce...

To the Editor: W elders are at risk of a wide range of respiratory health problems, including bronchitis, airway irritation, and lung function changes.1–5 Despite short duration of exposure, an inception cohort study of apprentice welders in Quebec documented a significant respiratory function decline, incidence of welding-related respiratory symptoms suggestive of occupational asthma and sensi...