X射线荧光光谱法测定易切削不锈钢中铅碲铋

在圆珠笔笔头最顶端的地方,材料厚度仅有0.3~0.4mm,需要极高的加工精度,对不锈钢原材料(易切削钢)提出了极高的性能要求。易切削钢是指在钢中加入一定量的S、P、Pb、Te等易切削元素,以改善其切削性的合金钢,钢中微量元素的准确分析直接影响到该钢种的冶炼成功与否。研究发现桶样分析稳定性更优于球拍样,因此实验采用铣床对桶样进行制样,刀头旋转速度为300r/min、进刀速度为250mm/min。通过对X射线荧光光谱仪晶体、2θ角和脉冲高度等基本分析条件优化后,使用标样绘制了易切削不锈钢样品中Pb、Te、Bi的回归曲线,回归精度(SEE)分别为0.0034、0.0027、0.0046,实现了X射线荧光光谱法(XRF)对易切削不锈钢中Pb、Te、Bi含量的测定。Pb、Te、Bi的检出限分别为0.0009%、0.0012%、0.0006%。用实验方法测定生产样品(编号3125)中Pb、Te和Bi含量,测定结果的相对标准偏差(RSD,n=11)均不大于1.1%;对易切削钢生产样品进行正确度分析,分析结果与化学湿法、火花放电原子发射光谱法一致性较好。

Determination of lead,tellurium and bismuth in free-cutting stainless steel by X-ray fluorescence spectrometry

The thickness of material on the top of ball-point pen was only between 0.3-0.4mm, which required very high machining precision. It put forward very high demands to the performance of stainless steel raw material (free-cutting steel). In free-cutting steel, some free-cutting elements such as S, P, Pb and Te were added into steel to improve the cutability of alloy steel. The accurate analysis of these microelements directly influenced on the success of steel smelting. It was found that the analysis of bucket sample had better stability than that of racket sample. Therefore, the sample was prepared from bucket sample with milling machine. The rotation speed of cutting head was controlled at 300r/min and the feeding speed was 250mm/min. The fundamental analysis conditions such as X-ray fluorescence spectrometer crystal, 2θ angle and pulse height were optimized. The certified reference material (CRM) was developed to draw the regression curves for Pb, Te and Bi in free-cutting stainless steel. The standard errors of estimate (SEE) were 0.0034, 0.0027 and 0.0046, respectively. The determination of Pb, Te and Bi in free-cutting stainless steel by X-ray fluorescence spectrometry (XRF) was realized. The detection limits for Pb, Te and Bi were 0.0009%, 0.0012% and 0.0006%, respectively. The proposed method was applied for the determination of Pb, Te and Bi in production sample (Number of 3125). The relative standard deviations (RSD, n=11) of determination results were all not more than 1.1%. The trueness analysis of free-cutting steel production samples was performed. The analytical results were in good agreement with those obtained by chemical wet method and spark discharge atomic emission spectrometry.