Particle size distribution of gas metal and flux cored arc welding fumes

A cascade impactor was employed to separate the fume particles in order to determine the size distribution of welding fume. Clear images of coarse welding fume particles (microspatter) from scanning electron microscopy are presented. The particle size distribution of the welding fume reveals that gas metal arc welding (GMAW) fume consists predominately of particle agglomerates smaller than approximately one micrometer. Less than 10% of the fume by weight is microspatter, which is larger than a micrometer. This fraction of microspatter does not change greatly as the GMAW parameters are changed. Flux cored arc welding (FCAW) fume contains more microspatter, approximately 30% by weight.