X射线荧光光谱法分析高碳铬镍生铁中7种元素

高碳铬镍生铁是不锈钢冶炼的前期产品,该钢中C、Si、Cr、Ni含量高,高含量元素间的谱线干扰给样品分析的准确度带来较大影响,提高该钢中主元素分析的准确度是降低不锈钢冶炼成本的关键。实验通过铣床参数的组合优化,确定了样品表面制备的最佳参数。通过X射线荧光光谱法分析条件的优化,确定了在40 kV电压和70 mA电流下,Si、Cr、Ni使用固定道分析谱线,C、Mn、P、S使用Kα1,2扫描道分析谱线;C使用AX16C晶体,Si使用InSb晶体,P和S使用Ge111晶体,Mn、Cr、Ni使用LiF200晶体;同时C使用2.60°超粗准直器,其他元素使用0.25°中粗准直器;在4~6 s时间内进行分析的试验条件。使用标准样品对C、Ni采用浓度乘法校正,对Si采用强度加法校正,对S采用浓度加法校正,对Mn、P、Cr采用强度乘法校正,绘制了C、Si、Mn、P、S、Cr、Ni 7个主元素的分析曲线,各曲线回归的相关系数在0.996 7~0.999 9之间。对实验方法进行了长期和短期精密度验证,分析结果的相对标准偏差(RSD,n=11)在0.019%～2.0%之间。正确度试验显示:样品的分析结果与参考值吻合较好。对日常分析中,时常出现的手指接触分析面,或是在样品表面被污染时用乙醇清洁的情况进行了试验比对,给出只有在不关注C元素分析结果时,才能对样品表面进行乙醇清洁处理。实验方法用于高碳铬镍生铁的分析可提高准确度,降低不锈钢冶炼成本。

Analysis of seven elements in high-carbon-chromium-nickel pig iron by X-ray fluorescence spectrometry

High-carbon-chromium-nickel pig iron was the early-stage product in stainless steel smelting. The content of carbon, silicon, chromium, and nickel in such steel was high. The spectral line interference among these high content elements had a great impact on the accuracy of sample analysis. Improving the analysis accuracy of main elements in such steel was the key to reduce the cost of stainless-steel smelting. Through the combination optimization of milling machine parameters, the optimal parameters for sample surface preparation were obtained in experiments. By optimizing the analysis conditions of X-ray fluorescence spectrometry, the following analytical conditions were determined: the voltage and current was 40 kV and 70 mA, respectively; Si, Cr and Ni adopted monochromators, while C, Mn, P and S adopted goniometers of Kα1,2; the crystal of AX16C was used for C, the crystal of InSb was used for Si, the crystal of Ge111 was used for P and S, and the crystal of LiF200 was used for Mn, Cr and Ni; meanwhile, the collimator of 2.60° was used for C, and the collimator of 0.25° was used for the other elements; the analytical time was 4-6 s. During the preparation of analytical curves for seven elements including C, Si, Mn, P, S, Cr and Ni, Multiplicative Concentration was used for C and Ni, Additive Intensity was used for Si, Additive Concentration was used for S, and Multiplicative Intensity was used for Mn, P and Cr. The correlation coefficients of curves were between 0.996 7 and 0.999 9. The long-term and short-term precision of the experimental method was verified. The relative standard deviations (RSD, n=11) of analytical results were between 0.019% and 2.0%. The accuracy test showed that the analysis results of sample were in good agreement with the reference values. In daily analysis, when the finger contacted the analytical surface, or when the analytical surface was polluted, it was cleaned with ethanol. The results showed that the sample surface could be treated with ethanol only when the carbon analysis results were not concerned. The proposed method was applicable for the analysis of high-carbon-chromium-nickel pig iron. It could improve the accuracy and reduce the cost of stainless steel smelting.