Study of the ultraviolet emission of the electrode coatings of arc welding

Abstract

The optical emission properties of several minerals components employed in electrode coatings of arc welding have been investigated. The X-ray diffraction analysis shows that the composition of 14 commercial electrode coatings collected from different countries (Spain, France, UK, Poland, Argentina and Germany), consists of quartz, calcite, sodium and potassium rich feldspars, muscovite and rutile. The natural thermal stimulated luminescence (TSL) of these mineral phases, measured in the range of 200 – 800 nm at different temperatures (from room temperature to 400°C) displays UV-A (wavelengths of 320 nm to 400 nm) and UV-B (from 280 nm to 320 nm) emissions, with the exception of rutile. The UV-B radiation, commonly described as the most dangerous form of radiation to human life, is here associated with structural defects in the crystallographic lattice of the mineral components of electrode coatings.

Keywords:

• Ultraviolet emission
• thermoluminescence
• minerals coatings
• spectra
• electrodes

Acknowledgements

The authors are grateful to Prof. Dr. P.D. Townsend for the guidelines for the experiments and to Dr. M.L. Clarke for the TL measurements using the high sensitivity TL spectrometer of the Univ. of Sussex (UK) and to Paul Giblin for the critical review of the manuscript. This work has been funded by the CICYT project BFM2002-00048.