Features of fume distribution in the working zone during arc welding operations with various covered electrodes

Abstract

Particles in welding fumes (WFs) generated through arc welding operations pose serious health concerns to the welders through their exposure to heavy metals. In this study, the influence of different covering types of industrial electrodes (rutile, basic, acid, rutile-cellulose) on the particle size distribution, morphology, and elemental composition of particles of welding fumes was investigated. Quantitative analysis was conducted in order to determine the distribution of particles with diameters of 10μm, or less, (PM10 fraction) of the WFs within the workplace, followed by the comparison of the results with the current international normative documents on the maximum permissible concentration of the PM10 fraction in the working zone air. The most hazardous types of electrode coverings were determined based on the dispersion, chemical composition, and concentration of formed particles of the PM10 fraction in space and time. The dependence of the particle size distribution time of the WFs in the working zone was identified for a basic covered industrial electrode. The maximum sizes of WF particles were reported for operations held at 100 A with electrodes having the rutile-cellulose type of covering, and at 150 A having the basic type of covering. A concentration of 0.05 mg/m3 for the PM10 fraction of WFs in the workplace was achieved after 1 hour of the welding machine operation at a current equal to 100 A. Thus, the results of the characterization of WFs demonstrate the risks of the arc welding process to human health and stress the need for their control and mitigation. According to the results of the study, a proportional relationship between the average particle diameter and the WF particle distribution period in the workplace has been demonstrated, which has been particularly evident from the height of the WF particles. 3D modeling of the dispersion of WF particles during welding arc operations proved to be a suitable method for their characterization.