A method has been devised for simultaneously determining the concentrations of La, Ce, and Pr in carbon steels. The samples are dissolved and their solutions sent through small amounts of ion exchange resin. The dried resin is pelletized and the L, X-ray fluorescence intensities of the rare earths are obtained. The intensities are compared to a curve obtained from previously prepared elemental standards. Precision of the standard curves is 8-14 rg, and detection limits are 0.002-0.0040/,, based on a 2-gram steel sample.THE USE of rare earths in steel has been primarily for inclusion shape control. The rare earth sulfides tend to form spherical
A new spectrographic method for the determination of boron in carbon and alloy steels has been developed by which accurate, precise, and rapid determinations of boron in the range 5–90 ppm are obtained. In this new procedure, a condensed overdamped discharge is used to excite the spectrum, the sample's electrical polarity is negative, and the graphite counter electrode has a pointed tip with an included angle of 15°. The repeatability of the method expressed as the coefficient of variation is ±5.8%; and at a 95% confidence interval, the spectrographic results agree with chemical determinations within ±22% of the amount present in the sample.
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