METHOD FOR MEASURING Ti COATING MASS OF TITANIUM-BASED CHEMICAL CONVERSION COATING FORMED ON SURFACE TREATED STEEL PLATE

摘要

PROBLEM TO BE SOLVED: To accurately measure a Ti coating mass by offsetting effects of a Ti content and a plating mass of a substrate steel plate when the Ti coating mass is to be measured by X-ray fluorescence analysis of a titanium-based chemical conversion coating formed on a surface of a surface treated steel plate. SOLUTION: When the Ti coating mass is to be measured on the basis of a fluorescent X-ray intensity by exposing to X rays a sample to be measured of the surface treated steel plate having the titanium-based chemical conversion coating formed, constants IBG, A, a, h0, and constants B and b dependent on the Ti content of the substrate steel plate are preliminarily determined and the Ti fluorescent X-ray intensity obtained from the sample to be measured is substituted in the equation (1) of IP=IB+hS wherein (2) IB=IBG+A.Cexp(-aW), (3) h=h0+Bexp(-bW), C is the Ti content of the substrate steel plate and W is the plating mass. The Ti coating mass S is thus calculated.