Physicochemical characterisation of different welding aerosols

Abstract

Physicochemical properties important in exposure characterisation of four different welding aerosols were investigated. Particle number size distributions were determined by scanning mobility particle sizer (SMPS), mass size distributions by separation and weighing the individual size fractions of an 11-stage cascade impactor. The size distribution of the primary particles of agglomerates, chemical composition and morphology of the particles were examined by TEM. There were significant differences in the particle number size distributions of the different welding aerosols according to the SMPS determinations. The particle mass size distributions determined gravimetrically were, however, not really different. The dominant range with respect to mass was between 0.1 and 1 μm, regardless of the welding technique. Most of the primary particles in all different welding aerosols had diameters between 5 and 40 nm. All types of primary particles had a tendency to form chainlike agglomerates. A clear size dependence of the particle chemical composition was encountered in the case of manual metal arc welding aerosol. Small particles with diameters below 50 nm were mostly metal oxides in contrast to larger particles which also contained more volatile elements (e.g. potassium, fluorine, sodium, sulphur).

Levels and predictors of airborne and internal exposure to manganese and iron among welders

“…22 Metal oxides in welding aerosols are usually small in size, with particle diameters frequently below 50 nm. 23 Mn occurs in welding fume as oxides that can form spinels or spheric particles together with other metals, including iron. It is unknown how this complex chemistry influences the bioavailability of Mn and Fe.…”

The effect of metal transfer modes and shielding gas composition on the emission of ultrafine particles in MAG steel welding

“…Similar studies have also been done for welding fumes generated in other processes, such as manual metal arc welding (MMA) and tungsten inert gas welding (TIG) [13]. However, these did not address the deposited surface area of emitted particles.…”

Simulation of “Aerosol Particles – Air Ions” System in Working Area Applied to Engineering Production

“…На современном этапе развития машиностроительного производ-ства актуальность проблемы обеспечения безопасности и качества воз-духа рабочей зоны усугубляется увеличением выбросов в воздух рабо-чей зоны высокодисперсных аэрозольных частиц (диаметром от по-рядка нанометра до, по крайней мере, сотен нанометров), в том числе и электрически заряженных (тяжелых аэроионов) [7][8][9][10][11][12][13][14]. Увеличение доли высокодисперсных частиц связано с технологическим и техниче-ским перевооружением, а именно с всевозрастающими скоростями, сложностью и точностью обработки материалов, с всё более широким внедрением на различных производствах пластмассовых, полимерных и композитных материалов и обрабатываемых деталей из высокопроч-ных сплавов, в том числе полученных при помощи нанотехнологий.…”