XRFS Determination of Mass of Plating Layer of Galvanized Steel Sheet

XRFS was applied to the determination of mass of plating layer of galvanized steel sheets, including masses of Zn-layer, Zn-Fe alloy layer, Cr-bearing passivation layer, phosphorized layer, passivation layer without Cr and fingerprint proof layer. Preparation of series of standard samples used for the analysis was described in detail. In the XRFS analysis, the fluorescence intensities of the characteristic elements were measured and their masses per square meter (g·m-2) were found from the standard curves. Different time of measurements was chosen according to the magnitude of fluorescence intensity of spectrum of the respective elements determined, and an area with 30 mm in diameter was chosen for the measurements. Standard samples with similar composition should be used in the analysis. Samples of each of the above mentioned 6 layers were taken and replicate determinations were carried out, giving values of RSD′s (n=10) in the range from 0.10% to 0.32%. Values of masses of plating layers found by the present method were checked by the gravimetric and ICP-AES methods, and no significant difference among the data was found as shown by the results of t-test (α=0.05).