Case studies: comparing exposure levels by type of welding operation and evaluating the effectiveness of fume extraction guns.
Wallace-ME; Shulman-SA; Sheehy-JW
Appl Occup Environ Hyg 2001 Aug; 16(8):771-779
Plant and Process Description: The evaluation was conducted in a plant that manufactured steam ovens for use in commercial and military kitchens. Fabrication of the steam ovens primarily involved straight-line welding of stainless and boilerplate (carbon) steel. The three main welding techniques used at this site were solid-wire gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), and flux-cored arc welding (FCAW). GMAW and GTAW were used to weld stainless steel (SS) parts, while FCAW was used to weld boilerplate. During GMAW, a solid-core wire consumable is continuously fed through a welding gun while a shielding gas is supplied at the gun tip to prevent oxidation of the base metal. At this site, the GMAW shielding gas was a mixture of argon and carbon dioxide. The FCAW technique is similar to GMAW, except that the wire is hollow and filled with a flux core. The flux can be composed of various metals or minerals that promote the weld process by removing impurities and preventing oxidation. A carbon dioxide shielding gas was supplied during FCAW. In comparison, the GTAW technique uses a welding gun equipped with a fixed, non-consumable tungsten electrode to generate the arc. A consumable stainless steel electrode is held near the arc to supply filler metal. An argon-based shielding gas was used at this during GTAW.
Exposure-levels; Welding; Welding-industry; Stainless-steel; Tungsten-compounds; Metals
Work Environment And Workforce; Research Tools and Approaches; Exposure Assessment Methods
Applied Occupational and Environmental Hygiene