Characterization of airborne particles generated from metal active gas welding process

Abstract

This study is focused on the characterization of particles emitted in the metal active gas welding of carbon steel using mixture of Ar + CO₂, and intends to analyze which are the main process parameters that influence the emission itself. It was found that the amount of emitted particles (measured by particle number and alveolar deposited surface area) are clearly dependent on the distance to the welding front and also on the main welding parameters, namely the current intensity and heat input in the welding process. The emission of airborne fine particles seems to increase with the current intensity as fume-formation rate does. When comparing the tested gas mixtures, higher emissions are observed for more oxidant mixtures, that is, mixtures with higher CO₂ content, which result in higher arc stability. These mixtures originate higher concentrations of fine particles (as measured by number of particles by cm³ of air) and higher values of alveolar deposited surface area of particles, thus resulting in a more severe worker's exposure.

• Alveolar deposited surface area
• arc welding
• particles
• welding fumes

Acknowledgements

J.G. and R.M. acknowledge the support of Fundación MAPFRE, Madrid, Spain through a Beca I. Hernando de Larramendi. C.G., R.M. and T.S. acknowledge Pest OE/EME/UI0667/2011, and PC acknowledge Pest OE/CTM/UI0084/2011 from the Portuguese Fundação para a Ciência e a Tecnologia (FCT-MEC).