超声辅助盐酸提取-电感耦合等离子体发射光谱法测定焊接药剂中磷

熔炼焊剂、烧结焊剂等焊接药剂由多种硅酸盐、碳酸盐、氧化物、氟化物、铁合金、金属粉等无机物及有机物经熔炼、烧结、粘结或混合制成，在钢铁和镍基合金的熔化焊接过程中起到造渣、脱氧、造气、稳弧、合金化等作用，广泛应用于船舶、海工、能源、冶金、化工、机械等行业领域。磷是焊接药剂及钢铁材料的有害元素，引发冷脆，降低熔敷金属和焊缝的力学性能。准确和快速地测定磷含量对焊接药剂的性能评价、质量控制等具有重要意义。研究了超声辅助盐酸提取—电感耦合等离子体发射光谱法测定焊接药剂中磷的方法，并优化确定了射频功率、雾化气流量、辅助气流量、等离子体气流量与分析谱线等仪器参数。确定的工作参数如下，射频功率：1.2 kW，雾化气流量：0.75 L·min-1，辅助气流量：1.0 L·min-1，等离子体气流量：12 L·min-1，选择P 213.617 nm为分析谱线。称取0.5 g试样，于20 mL盐酸中超声浸取30 min；加入2 mL硝酸，加热煮沸溶液，冷却后定容至100 mL，干过滤取滤液待测。以20 mL盐酸和2 mL硝酸为基体配制系列校准曲线溶液，线性相关系数大于0.999 9。方法定量限为0.001 2%。按实验方法测定磷含量为0.003%~0.03%的实际样品和标准样品，测定结果与标准方法的测定值或标准样品的认定值相符，相对标准偏差（n=6~10）不大于8%，加标回收率为93%~110%。该方法快速准确、简便可行，适用于焊接药剂中磷的快速检验。

Determination of Phosphorus in Welding Flux by Inductively Coupled Plasma Atomic Emission Spectrometry With Ultrasonic Assisted Hydrochloric Acid Extraction

Welding flux, such as fused and agglomerated flux, are composed of various inorganic and organic minerals such as silicates, carbonates, oxides, fluorides, iron alloys and metal powder. They are prepared by smelting, sintering, binding or mixing. Welding flux would play an important role in slagging, deoxidation, gas making, arc stabilization and alloying in the fusion welding of steel and nickel-based alloys. They have been widely used in the engineering fields, including shipbuilding, ocean engineering, energy, metallurgy, chemical, and machinery. Phosphorus is a trace and harmful impurity element in iron, steel and nickel-based alloy materials, which could reduce the mechanical properties of materials by causing embrittlement and micro-cracks in deposited metals and welded seams. The accurate and rapid determination of phosphorus in welding flux is significant to performance evaluation and quality control. Working conditions for determining phosphorus in welding flux by inductively coupled plasma atomic emission spectrometry with ultrasonic-assisted hydrochloric acid were optimized, such as radio frequency power, gas flows of atomization, auxiliary and plasma, and analysis line. The optimized operating parameters were obtained below: The radio frequency power was set to 1.2 kW, and the gas flows of atomization, auxiliary and plasma were set to 0.75, 1.0 and 12 L·min-1, respectively. P 213.617 nm was selected as the analysis line. The sample suspension was prepared with a 0.5 g welding flux sample in 20 mL hydrochloric acid with ultrasonic-assisted extraction for 30 min and was heated to boiling with 2 mL nitric acid. After cooling, the volume of suspension was adjusted to 100 mL by pure water. Then the suspension was dry filtered, and the filtrate was used for measurement. A series of solutions for developing a calibration curve was prepared with 20 mL hydrochloric acid and 2 mL nitric acid as the matrix. The linear correlation coefficient of the calibration curve was 0.999 9, and the quantification limit was 0.0012%. The actual sample and certified reference materials of welding fluxes with phosphorus between 0.003% to 0.03% were determined, and the results were consistent with the certified or obtained the standard. The relative standard deviations (n=6~10) of determination results were less than 8%, and the recoveries were between 93% to 110%. The proposed method has the advantages of accuracy, fast and convenience. It is suitable for the rapid inspection of phosphorus in welding fluxes.