Determination of 11 elements in 300 series stainless steel by X-ray fluorescence spectrometry
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 deter-mination 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 se-ries 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 re-sults showed that the correction effect of COLA equation on Cr was much better than the De Jongh equa-tion.However,for Ni with comparative content range,there was no significant difference.The possible rea-son 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(αCr,Fe and αCr,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(αNi,Fe and αNi,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 re-duce the overlapping interference among spectral lines.The further scanning showed that only the overlap-ping interference correction of CrKβ1,3 to MnKα1,2 and MoL1 to PKα1,2 was required.Therefore,the correc-tion was conducted by the empirical coefficient method based on concentration correction.The sample of 300 series stainless steel was determined for 11 times in parallel according to the experimental method.The results showed that the RSDs of determination values were all less than 1%when the element contents were higher than 0.1%.As the element contents were lower than 0.1%,the RSDs were all less than 10%.Three standard samples(which were not selected for the preparation of calibration curves)and two pro-duction samples of stainless steel were determined according to the experimental method,and the found re-sults were consistent with the standard values of certified reference materials or those obtained by the wet method.
300 series stainless steelX-ray fluorescence spectrometry(XRF)matrix correctionCOLA e-quationDe Jongh equationspectral line overlapping correctiontheoretical α coefficient methodalloying element
张祥、缪乐德、张毅
展开 >
宝山钢铁股份有限公司中央研究院,上海 201900
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