Rf glow discharge optical emission spectrometry for cleaning process control of oil residues in low alloy steel

Radiofrequency glow discharge optical emission spectrometry (rf-GD-OES) has been investigated as an assessment tool in the control of cleaning processes developed to remove oil residues covering the surface of the steel. The control of the cleaning process has a special importance on the production of zinc and zinc alloy coatings on steel as a corrosion protection. One of the most important methods used in producing zinc coatings is the immersion of steel in a liquid bath of zinc or a zinc alloy. Therefore, prior to this immersion, the cleaning of oil residues remaining on the steel sheet from previous processing steps is of great importance. Two cleaning processes have been investigated. Qualitative and quantitative rf-GD-OES results have been used to control the carbon-based impurities present on the surface of the steel sheet.