It is well khown that welding arcs emit intense ultraviolet radiation and those who conduct welding operations or work nearby are exposed to the radiation and often suffer injuries. It is desirable to evaluate the ultraviolet radiation from the viewpoint of industrial health. But, there have been few quantitative studies of this radiation. We determined the ultraviolet effective irradiance, bas...

HUNDREDS OF THOUSANDS of people work in welding, cutting and brazing. It is estimated that welders compose 1 to 2% of the U.S. working population, including a significant segment of the aging workforce. According to OSHA’s Christine Petitti, the most commonly used welding processes are: 1) Flux-cored arc welding (FCAW). This process uses an arc between a continuous filler metal electrode and th...

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 ...

Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by a shielding gas (usually an inert gas such as argon), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it. A const...

The use of time-frequency entropy to quantitatively assess the stability of alternating current square wave submerged arc welding process considering the distribution features of arc energy is reported in this paper. Time-frequency entropy is employed to calculate and analyze the current signals under different duty cycle, frequency and welding speed in the submerged arc welding process. It is ...

Most previous welding simulations are based on a flat weld pool surface and become unmeaningful when the surface deformation is significant. In recent years, some researchers have developed numerical models capable of simulating free surface motion in welding processes, but they focus on the discussions of physical equations, boundary conditions, and solutions, rather than the numerical algorit...

An approach for modelling thermo-mechanical responses in a 3D arc welding process is developed using the Smoothed Particle Hydrodynamics (SPH) method. It is demonstrated for a simple arc welding configuration by using full three-dimensional elastoplastic analysis. The flow pattern of the filler material and the resulting plastic strain distribution are analysed. The effect of welding speed on t...

The objective of this study was to characterize personal exposures to welding-related metals and gases for production welders and non-welders in a large manufacturing facility. Welding fume metals and irritant gases nitrogen dioxide (NO2) and ozone (O3) were sampled for thirty-eight workers. Personal exposure air samples for welding fume metals were collected on 37 mm open face cassettes and ni...

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...

An adaptive control based on fuzzy logic has been implemented for Gas Tungsten Arc Welding (GTAW). This adaptive controller eliminates the problems frequently experienced with traditional Automatic Voltage Control (AVC) systems, which do not adequately perform for all operational conditions because of the non-linear relationship between the arc voltage, current and arc length. This paper examin...