Researches on selection and action mechanism of flux for the determination of trace sulfur in high manganese sainless steel by high frequency combustion-infrared absorption method.

Aimed at the phenomenon that the determination results of trace sulfur in high manganese stainless steel by high-frequency combustion infrared absorption method was seriously low, with high manganese stainless steel Cr18Ni5Mn10Mo3 and GH139 as test samples, the influence of type, proportioning, adding order of flux and sample weight was studied. At the same time, the high-temperature oxidation behavior and action mechanism of flux was discussed with the help of thermal analyzer, which provides a theoretical basis for flux selection. The test results showed that the optimal flux dosage and sample adding order for stainless steel Cr18Ni5Mn10Mo3 and GH139 respectively were 0.5 g of pure iron + 0.25 g of sample + 0.5 g of tin + 2.5 g of tungsten, and 0.5 g of tin +0.7 g of pure iron + 0.20 g of sample + 0.5 g of mixture of molybdenum trioxide and vanadium pentoxide (m(MoO3) : m(V2O5)) + 1.5 g of tungsten, respectively. Sulfur in the two high-manganese stainless steel standard samples was determined by this method, with the measured values in consistency with the certified values and the relative standard deviation of the measurement results in 7.2% and 4.5% (n = 6), respectively.