Abstract
Ni-Zn electroplated steel shows good corrosion resistance. It is important in the production of the electroplated steel to control the concentration of Ni2+ and Zn2+ in plating bath. An on-line analysis instrument by fluorescent X-ray analysis was developed for the process control.
(1) The analyzer consists of sampling-line and X-ray analysis instrument. The plating solution is fed to the X-ray analysis instrument through sampling-line from plating trays. These operations are done fully automatically.
(2) Fluorescent X-ray analysis system with energy dispersive method is used. It is necessary to correct the concentration of SO42- and Fe2+ in determination of the concentration of Ni2+ and Zn2+. Measuring of fluorescent X-ray of S is easy in the air by the analysis system.
(3) For X-ray source, W target is used for excitation of Ni, Zn, and Fe fluorescent X-ray, and Cr target for S fluorescent X-ray, respectively.
(4) The analytical accuracy in on-line analysis was 0.77 g/l and 0.48 g/l for Ni2+ and Zn2+, respectively. The time required for one cycle analysis is eight minutes.
(5) This analyzer has been running for about two years without any trouble.
