1995 Volume 81 Issue 11 Pages 1067-1072
Al-Mn electroplated galvannealed steel sheet has been developed due to its corrosion-resistibility. In the analyses of metal coatings, the x-ray fluorescence analysis (XRFA) has been applied because of its advantage on speed and nondestructive nature. The XRFA needs, in general, the analytical curves that describe the relationships between the fluorescent x-ray intensity and the coating weight or the composition. To establish the analytical curve, many standard specimens are required, that need lots of money and time to prepare.
Although the standard-less analysis technique of XRFA known as the fundamental parameter (FP) method has solved this problem, it sometimes brings errors to the analytical values. It is because the FP method assumes that the specimen is completely free of inhomogeneity, i.e. the coating weight and the composition is constant at least over the irradiated area.
Therefore, we developed the analysis method for the specimens that have inhomogeneity to some extent ; the measured intensity was corrected according to the inhomogeneity ; using this corrected intensity, the specimens were analyzed by FP method. As a result, the Al-Mn coating weight and the Mn concentration were determined as accurate as 0.24 g/m2 and 0.96 mass%, respectively.
