脉冲熔融-红外吸收法测定镧铈合金中氧

Determination of oxygen in lanthanum-cerium alloy by impulse fusion-infrared absorption method

为满足国内稀土钢研制的需要,与镧、铈及镧铈合金提纯研究同步,逐步建立脉冲熔融-红外吸收法对镧铈合金中杂质氧的测定方法。考察了称样量、分析功率、不同(助熔)浴料对分析结果的影响。找出熔体平滑、峰形好的最佳分析功率4200W,称样范围为0.10~0.20g。从助熔剂法和浴料法中筛选并确定Cu-Sn-Fe-Ni四元浴,自制配方比例为3∶3∶1∶1(质量比);尝试“样品与标样间隔投样校正法”定量评估和抵消仪器(被污染)产生的干扰。实测范例显示:目前国内镧铈合金样品中氧质量分数可低至0.00679%;相对标准偏差(RSD,n=7)为5.5%。以钢中氧标准样品GBW(E)020143进行加标回收试验,回收率为101%~105%;另通过与辉光放电质谱法方法对比,一致性较好。

In order to meet the development requirements rare earth steels in China,and to synchronize the study of purification for lanthanum,cerium and lanthanum-cerium alloys,the determination method of impurity oxygen in lanthanum-cerium alloy by impulse fusion-infrared absorption was established.The effect of sample mass,analysis power and different(fluxes)baths on the analysis results was investigated.The melt was smooth and the peak shape was good under the following conditions:the analysis power was 4200W;the sample mass was in range of 0.10-0.20g.Cu-Sn-Fe-Ni quaternary bath with mass ratio of 3∶3∶1∶1 was selected in experiments.The interference of instrument(be contaminated)was quantitatively evaluated and offset by“Sample-STD-sample calibration method”.The determination results of actual samples indicated that the mass fraction of oxygen in domestic lanthanum-cerium alloy samples at present could be low to 0.00679%.The relative standard deviation(RSD,n=7)was 5.5%.The spiked recovery tests were conducted using standard sample of oxygen in steel,i.e.,GBW(E)020143.The recoveries were between 101%and 105%.In addition,the determined results were in good agreement with those obtained by glow discharge mass spectrometry.