高频熔融制样-X射线荧光光谱法测定镍-铜-铁合金中镍铜铁锡磷硫

镍-铜-铁合金为不规则样品,采用离心浇铸法制样时单次只能制备一个样品。实验采用多功能熔融炉高频熔融浇注制备成蘑菇状块状样品,实现了X射线荧光光谱法(XRF)对镍-铜-铁合金中镍、铜、铁、锡、磷和硫含量的测定。通过优化多功能熔融炉工作参数,采用程序控制阶梯式升温,5段号加热及保温的方式对样品进行熔融,确定了最佳的样品制备工艺。实验表明,当最大目标功率12.75kW,每个段号的升温时间10s,整个熔融时间10min时,熔融制备出的样品中各待测元素化学成分在0～0.50mm不同深度方向具备良好的均匀性,相同熔融条件下的样品重复性良好。选用一定含量梯度的镍合金、镍铬合金、高合金钢光谱标准样品和化学定值的镍-铜-铁合金内控样品制作校准曲线,各待测元素线性相关系数均大于0.999,检出限在12.35～42.21μg/g之间,制备10次块状样品的分析结果的相对标准偏差在0.15%～1.9%(n=10)之间。实验方法应用于镍-铜-铁合金实际样品的测定,与标准方法测定结果具有较好的一致性,满足常规检测的需求。

Determination of nickel,copper, iron,tin, phosphorus and sulfur in nickel-copper-iron alloy by X-ray fluorescence spectrometry with high-frequency fusion sample preparation

Nickel-copper-iron alloy belongs to irregular sample and only one sample could be prepared in single sample preparation by centrifugal casting method. A multi-functional melting furnace was used to prepare the mushroom-shaped block samples by high-frequency fusion casting. The determination of nickel, copper, iron, tin, phosphorus and sulfur in nickel-copper-iron alloy by X-ray fluorescence spectrometry (XRF) was realized. The working parameters of the multi-functional melting furnace were optimized. The program-controlled step heating was used, and the heating and heat preservation of the 5th stage were adopted to melt the samples. The optimal sample preparation process was obtained. The experimental results showed that when the maximum target power was 12.75kW, the heating time of each stage was 10s, and the entire melting time was 10min, the chemical composition of each testing element in the sample with fusion preparation had good homogeneity in the depth direction of 0-0.50mm. Moreover, the repeatability of sample was good under the same melting conditions. The calibration curve was established using spectral standard samples of nickel alloy, nickel-chromium alloy and high-alloy steel and chemically-defined internal control samples of nickel-copper-iron alloy with certain concentration gradients. The linear correlation coefficients of all testing elements were higher than 0.999. The limits of detection were between 12.35μg/g and 42.21μg/g. The relative standard deviations (RSD, n=10) of determination results of ten block samples were between 0.15% and 1.9%. The proposed method was applied to the determination of nickel-copper-iron alloy actual samples. The found results were in good agreement with those obtained by standard method, which could meet the testing requirement of routine analysis.