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 Crl8Ni5MnlOMo3 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 Crl8Ni5Mnl0Mo3 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% (w=6), respectively.%针对高频燃烧红外吸收法测定高锰不锈钢中痕量硫的结果严重偏低现象,以Cr18Ni5Mn10Mo3和GH139高锰不锈钢为试验样品,考察助熔剂的种类、配比、加入顺序及称样量对测定的影响.同时,借助热分析仪对助熔剂的高温氧化行为进行了分析,探讨了助熔剂的作用机理,为助熔剂的选择提供了理论依据.试验结果表明,Cr18Ni5Mn10Mo3和GH139不锈钢的最佳助熔剂用量及样品加入顺序分别为0.5g纯铁+0.25 g样品+0.5g锡+2.5g钨和0.5g锡+0.7 g纯铁+0.20 g样品+0.5g三氧化钼和五氧化二钒的混合物(m(MoO3)∶m(V2O5)) +1.5 g钨.用本方法测定了2个高锰不锈钢标准样品中的硫量,测定值与认定值相符,测定结果的相对标准偏差分别为7.2％和4.5％(n=6).
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