US EPA

1238140 

Journal Article 

Chemical Investigation of Welding Fumes from Hardfacing and HSLA-Steel Electrodes 

Tandon, RK; Ellis, J; Crisp, PT; Baker, RS; Chenhall, BE 

1986 

1 

Welding Journal
ISSN: 0043-2296 

NIOSH/00164079 

65 

9 

Detailed chemical analysis of the flux, fume, and water soluble fume fractions from three types of hardfacing and two types of high strength, low alloy (HSLA) shielded metal arc welding electrodes was performed. The five types of electrodes chosen for study are used extensively in the mining, chemical, and agriculture industries: hardfacing, medium chromium (7440473) (E01); HSLA steel (E04); HSLA steel direct current electrode positive; hardfacing, high manganese (7439965); and hardfacing, high chromium (E12). Analysis of electrode flux was carried out by x-ray fluorescence (XRF) and combustion. Fume from the electrodes was generated using an automatic arc welding machine. Analytical methods for evaluating fume included XRF, x-ray diffraction, atomic absorption spectrophotometry (AAS), ion selective electrode, and ion chromatography. Where elements were determined using both AAS and XRF techniques, agreement was excellent. In measuring water soluble fluorides by ion chromatography and ion select methods, variation was approximately +/10 percent, with ion chromatography probably the more accurate technique. Magnetite (1317619) and calcium-fluoride (7789755) were prominent in the crystal phases of four out of five fumes tested. Crystalline potassium-chromate (7789006) was present in fume from electrode E04, but absent from electrode E12. Up to 95 percent of total mass balances for flux, fume, and water soluble fume were obtained. An inverse relationship between fluoride (16984488) concentrations in fume and the fume generation rate was noted. Percentage of sodium (7440235) and potassium (7440097) in the flux was highly correlated with water soluble chromium(VI) (18540299) per total chromium in the fume. The authors conclude that guidance may be provided from this data for appraising the health status of welders, and situations related to fume exposure and toxicity. 

DCN-150657; Welding industry; Occupational hazards; Industrial hygiene; Chemical composition; Chromium compounds; Manganese compounds; Fluoride compounds; Calcium compounds