X射线荧光光谱法测定300系不锈钢中11种合金元素  

Determination of 11 elements in 300 series stainless steel by X-ray fluorescence spectrometry

作　　者：张祥 缪乐德[1] 张毅[1] ZHANG Xiang;MIAO Lede;ZHANG Yi(Central Research Institute of Baoshan Iron and Steel Co.,Ltd.,Shanghai 201900,China)

机构地区：[1]宝山钢铁股份有限公司中央研究院,上海201900

出　　处：《冶金分析》2024年第1期44-51,共8页Metallurgical Analysis

摘　　要：300系不锈钢为高Cr-Ni钢,合金元素间存在强烈的吸收增强效应,因此采用X射线荧光光谱法(XRF)分析300系不锈钢中的合金元素含量,必须校正样品中的基体效应。本实验采用XRF测定了15块300系不锈钢标准样品中的12种合金元素的X射线荧光强度,并绘制校准曲线,采用了两种理论α系数法校正基体效应,分别为De Jongh方程和COLA方程,结果表明,COLA方程对Cr的校正效果要明显优于De Jongh方程,而含量范围相当的Ni未表现出明显差异,这可能是因为在300系不锈钢中Cr主要受到Fe和Ni的增强作用,相应的理论影响系数α_(Cr,Fe)、α_(Cr,Ni)值随Fe、Ni含量变化而发生较大变化,其相对标准偏差(RSD)分别为10.4%、12.0%,而COLA方程能够根据元素含量变化而调整理论α系数值,适用于元素含量0~100%(质量分数,下同)范围的校正。Ni主要受到Fe和Cr的吸收作用,计算出的理论影响系数α_(Ni,Fe)、α_(Ni,Cr)值变化很小,RSD分别仅为1.6%和1.7%,因此,采用固定的理论α系数法,即De Jongh方程也能得到良好的效果。此外,300系不锈钢中合金元素间存在较强的谱线重叠干扰,实验采用分辨率更高的LiF220晶体和狭缝0.15°,以减少谱线间的重叠干扰,通过进一步扫描发现,仅需对CrKβ_(1,3)对MnKα_(1,2)、MoL_(I)对PKα_(1,2)的重叠干扰校正,为此,采用基于浓度校正的经验系数法进行校正。按照实验方法对300系不锈钢样品平行测定11次,结果表明,当元素含量在0.1%以上时,测得结果的相对标准偏差(RSD)均小于1%;当元素含量小于0.1%时,相对标准偏差均小于10%。选取了3个未参与校准曲线绘制的不锈钢标准样品和2个生产样品,按照实验方法进行测定,测定结果分别与标准样品标准值或湿法测定值相一致。300 series stainless steel belongs to high Cr-Ni steel,and there is strong absorption enhancement effect among alloying elements.Therefore,the matrix effect in sample must be corrected during the determination of alloying elements in 300 series stainless steel by X-ray fluorescence spectrometry(XRF).In this study,the X-ray fluorescence intensities of 12 alloying elements in 15 certified reference materials of 300 series stainless steel were determined by XRF,and the calibration curves were drawn.The matrix effect was corrected by two theoretical α coefficient methods,i.e.,De Jongh equation and COLA equation.The results showed that the correction effect of COLA equation on Cr was much better than the De Jongh equation.However,for Ni with comparative content range,there was no significant difference.The possible reason was that Cr in 300 series stainless steel was mainly affected by the enhancement effect of Fe and Ni,and the corresponding theoretical influence coefficients(α_(Cr,Fe) and α_(Cr,Ni)) varied greatly with the change of Fe and Ni contents.The relative standard deviation(RSD) was 10.4% and 12.0%,respectively.The COLA equation could adjust the value of theoretical α coefficient according to the change of element contents,so it was applicable for the correction of elemental content in range of 0-100%(mass fraction,the same below).Ni was mainly affected by the absorption of Fe and Cr,so the variation of calculated theoretical influence coefficients(α_(Ni,Fe) and α_(Ni,Cr)) was small,the RSD was only 1.6% and 1.7%,respectively.Therefore,good correction results could be achieved even if the fixed theoretical α coefficient(i.e.,De Jongh equation) was used.In addition,there was strong spectral overlapping interference among alloying elements in 300 series stainless steel.LiF220 crystal and slit of 0.15° with higher resolution were employed in experiments to reduce the overlapping interference among spectral lines.The further scanning showed that only the overlapping interference correction of CrKβ_(1,3

关 键 词：300系不锈钢 X射线荧光光谱法(XRF) 基体校正 COLA方程 De Jongh方程 谱线重叠校正 理论α系数法 合金元素 

分 类 号：O657.34[理学—分析化学] TF764.1[理学—化学]