抄録
Potentiostatic quantitative extraction of cementite and manganese sulfide in steel has been studied in order to establish a new method with a non-aqueous electrolyte instead of the conventional method using an aqueous electrolyte. As the non-aqueous electrolyte, 5% triethanolamine-1%LiCl-methylalcohol, 10% acetylacetone-1%LiCl-methylalcohol, 5% triethanol-amine-1% tetramethylammoniumchloride-methylalcohol, and 10% acetylacetone-1% tetramethyl-ammoniumchloride-methylalcohol were studied. Chemical stability of the extracted precipitates, potential-current curves of the steel samples and the pontential dependence of extraction ratio obtained by use of the non-aqueous electrolytes are compared with those when using aqueous 5% sodium citrate-1.2% potassium bromide (pH 5). Unstable precipitates such as cementite and manganese sulfide were found to be chemically stable in the non-aqueous electrolyte and to be quantitatively extracted. 10% acetylacetone-1% tetramethylammoniumchloride-methylalcohol was recommended as the non-aqueous electrolyte because of its high accuracy and reproducibility of the analytical results.
