火花放电原子发射光谱法测定奥氏体易切削不锈钢中高含量硫

奥氏体易切削不锈钢中S含量(质量分数,下同)大于0.2％,常规的测量方法有红外吸收法和电感耦合等离子体原子发射光谱法(ICP-AES),而上述分析方法存在制样慢、分析元素种类少等缺点,不能满足炉前炼钢的快速分析要求.实验采用火花放电原子发射光谱法研究了奥氏体易切削不锈钢中高含量S的分析技术.首先通过分析奥氏体易切削不锈...

Determination of high content sulfur in austenitic free-cutting stainless steel by spark discharge atomic emission spectrometry

The content of sulfur (mass fraction, similarly hereinafter) in austenitic free-cutting stainless steel is higher than 0.2%. The conventional measurement methods include infrared absorption and inductively coupled plasma atomic emission spectrometry (ICP-AES). However, these methods have some shortcomings such as slow sample preparation speed and few types of analytical elements, which cannot meet the rapid analysis requirements of steelmaking process. The analysis method of high content sulfur in austenitic free-cutting stainless steel by spark discharge atomic emission spectrometry was studied in experiments. The chemical and physical properties of austenitic free-cutting stainless steel sample were firstly analyzed, and the sample preparation method was investigated. Then the effects of measurement conditions and interference elements on the analytical results by spark discharge atomic emission spectrometry were discussed. The results showed that the sample preparation method of austenitic free-cutting stainless steel was unified to obtained the same measurement surface. New excitation electrode was used for the spark discharge atomic emission spectrometer. The austenitic free-cutting stainless steel sample was excited in the argon environment with purity not less than 99.995%. The precombustion time was 50 s and the measurement time was 12 s (800 Hz). The special calibration curve of sulfur with content range of 0.1%-0.4% in austenitic free-cutting stainless steel was drawn. The analytical results of high content sulfur in austenitic free-cutting stainless steel sample could be accurately obtained. For the austenitic free-cutting stainless steel samples with sulfur content of 0.122%, 0.264% and 0.387%, the relative standard deviation (RSD, n=11) of determination results was 3.8%, 1.3% and 0.81%, respectively. The t distribution critical value (t_0.975,9＝2.262) was adopted to check the analytical results of spark discharge atomic emission spectrometry and infrared absorption method, and the inspection result was less than the critical value. It indicated that there was no obvious different between the determination results of spark discharge atomic emission spectrometry and infrared absorption method. The proposed method could be used to stably determine the content of sulfur in austenitic free-cutting stainless steel.