Evaluation of carbon monoxide and microparticles concentrations generated during MAG-C welding process

Abstract

During the welding process, the filler wire - shielding gas couple generates the formation of pollutants which are dangerous for the welder's health. The research focussed on the quantitative evaluation of carbon monoxide (CO) and microparticles concentrations produced in MAG-C (Metal Active Gas-CO2) welding in various process conditions. Seven welding filler wires - one common solid wire, one basic flux-cored wire, three rutile flux-cored wires and two low fume rutile flux-cored wires- were selected for the investigation and comparative analysis of the pollutants developed by melting of these wires which were deposited by welding on EH36 shipbuilding steel sheets. Applying consecutively three feed rate values, twenty-one seam welds were performed in welding horizontal position within a special hermetically air-tight chamber. Concentrations of CO and microparticles were acquired through special devices - Multilyzer NG of gases and MicroDust Pro for microparticles - and then were processed and comparatively discussed. Using SEM analysis, measurement of particles' size was made and discussed in detail. The images obtained by SEM illustrated the formation of amorphous structures and also nano and micro-sized particles with diameters from 641,1 nm to 8,92 μm. The investigations revealed that the lowest concentrations of CO and microparticles were produced when solid and low fume rutile flux-cored wires were used in the deposition welding.

Keywords

• carbon monoxide
• CO2 shielding gas
• MAG-C welding
• microparticles
• pollutants