鋼中固溶マイクロアロイの定量

抄録

For the steel making control with the microalloy elements, it is essential to accurately analyze the solid solution content or precipitation content of the microalloy element in steel. The electrolytic extraction - filtration method has been used to determine all precipitations in steel, and the content of solid solution is obtained by the subtraction of the precipitation content from total content. But it has become inadequate to analyze the fine precipitates because some of the fine precipitates are unavoidably uncollected. Hence, we have developed a quantitative analysis for solute elements in steel by using of analyzing a portion of the electrolytic solution. By electrolysis, solute elements are dissolved into the electrolyte, and the precipitates remains on the surface of the sample. So, the analysis of the electrolytic solution during or after electrolysis enables the determination of solid solution content directly. For certified reference materials, the sum of the total content of solid solution determined by this method and the precipitates determined by the conventional method substantially agrees with certified value. However, for the samples that contain fine precipitates, they are not in agreement with the total content obtained by the spark-OES. It is estimated that the precipitates not collected by filtration in the conventional method cause the disagreement. It shows the proposed method, which analyzes solute solution directly, is useful.