火花放电原子发射光谱法分析低合金钢中酸溶铝的准确性探究  

Discussion on analytical accuracy of acid soluble aluminum in low alloy steel by spark discharge atomic emission spectrometry

作　　者：詹会霞 谷国雪 范瑾 ZHAN Hui-xia;GU Guo-xue;FAN Jin(CRRC DATONG Co.,Ltd)

机构地区：[1]中车大同电力机车有限公司,山西大同037038

出　　处：《冶金分析》2017年第12期50-54,共5页Metallurgical Analysis

摘　　要：采用脉冲分布分析测光(PDA)技术,以火花放电原子发射光谱法对低合金钢中酸溶铝的含量进行分析。讨论了3种制样方法(Al2O_3砂轮、SiC砂轮磨样及车铣)、氩气激发流量、压力及纯度对分析结果的影响,得出车铣制样方法为最佳选择,同时,控制氩气激发流量10L/min、输入压力0.20~0.30MPa及氩气纯度大于99.99%的实验条件。通过试验确定以Fe 287.2nm为内标线,Al 394.4nm为分析线,氩气冲洗时间3s,预燃时间1 700脉冲,积分时间3 600脉冲的分析条件。对校准曲线进行一次和二次线性拟合回归,发现后者效果更佳,相关系数达0.999 89。通过干扰元素V、Ti、Nb的重叠干扰校正,选择4种低合金钢标准样品进行精密度(n=10)和准确度考察,标样认定值与测定结果间的绝对误差、临界差CD0.95、标准偏差及重复性限对应的标准偏差均满足GB/T 4336—2016标准的规定要求,实验方法适合测定低合金钢中质量分数为0.008%~0.25%的酸溶铝含量。With the aid of pulse distribution analysis（PDA）technology,the content of acid soluble aluminum in low alloy steel was determined by spark discharge atomic emission spectrometry.The effects of three sample preparation methods（Al2 O3 grinding wheel,SiC grinding wheel and turn milling）,argon excitation flow rate,pressure and purity on analysis results were explored.It was found that the sample preparation by turn milling was the best choice.Meanwhile,the following experimental conditions were finally selected：the argon excitation flow rate was controlled at 10 L/min,the input pressure was 0.20-0.30 MPa,and the argon purity was higher than 99.99%.Fe 287.2 nm and Al 394.4 nm was used as internal standard line and analysis line,respectively.The flush time of argon was 3 s,the pre-burning time was 1700 pulse,and the integral time was 3 600 pulse.The calibration curve was regressed by linear fitting and quadratic fitting.The results indicated that the quadratic fitting was better with correlation coefficient of 0.999 89.The overlapping interference of V,Ti and Nb was corrected.Four kinds of low alloy steel certified reference materials were used for precision（n=10）and accuracy tests.The absolute error between the certified value and the determination value,the critical difference of CD0.95,the standard deviation and standard deviation corresponding to repeatability limit could meet the requirements in GB/T 4336—2016.The proposed method was applicable for the determination of acid soluble aluminum content with mass fraction of 0.008%-0.25%in low alloy steel.

关 键 词：火花放电原子发射光谱法 低合金钢 酸溶铝 准确性 

分 类 号：TG115.33[金属学及工艺—物理冶金]