高S含有鋼の真空溶融法による酸素分析

抄録

When high sulfur steels were analysed by the constant volume pressure measuring type vacuun fusion method, the sulfur gave positive errors on the determination of oxygen. The CS and CS₂ gases were generated by the reaction of sulfur and graphite crucible and then extracted together with CO from the crucible.
These CS and CS₂ were oxidized by the oxidizing reagent in the system and CO₂ and SO₂ were generated, the volume becoming two or three times. Of the sulfide generation the lower limit of sulfur content was about 0.1% in ordinary samples. To prevent these errors, a circulating system containing a Liq. O₂ trap was newly set in the apparatus and with it the sulfides in extracted gases were separated.
Thereby a good analytical precision (standard deviations were 3.7ppm and 14ppm for samples of 34ppm and 135.5ppm respectively.) was obtained on the determination of oxygen.
The components of the evaporated-condensed film on the inner wall of reaction tube and the residual metals in the crucible were analysed and the reaction mechanisms of evaporation, deposition, adsorption, and reduction of extracted gases and metals were discussed.