材料期刊网

硅钙合金作为钢铁和特殊合金生产过程中重要的脱氧剂和脱硫剂,目前还没有氧含量测定的国家标准方法.实验采用脉冲加热惰性气体熔融-红外吸收法建立了硅钙合金中氧含量的测定方法.考察样品粒度对分析结果精度的影响,确定最优粒度范围为120~150目(0.121~0.104 mm);进行了称样量条件试验,确定称取0.02 g试样最为合适;另外还考察分析功率条件和助熔剂的影响,确定5 000 W时,脉冲炉工作电流至少达到1080 A左右,采用镍箔作为助熔剂,包裹样品,样品熔融良好,释放完全.选择与待测样品氧含量接近的高氧铁粉参考物质JK47 (w(O)=1.09%),采用不同称样量,建立校准曲线,曲线的相关系数为0.995 1.结合校准曲线,确定方法的测定范围为0.2%~10%,方法的测定下限为0.000 41%.对硅钙合金样品进行精密度考察,氧测定结果的相对标准偏差(RSD)为1%左右,满足生产要求.采用高纯SiO2和CaO进行回收实验,回收率在95%~105%之间.

The silicon-calcium alloy is an important deoxidizing agent and desulfurizing agent in production of steels and special alloys.So far, there is no national standard method for the determination of oxygen in silicon-calcium alloy.A determination method of oxygen content in silicon-calcium alloy by pulse heating inert gas fusion infrared absorption method was established.The influence of sample particle size on the precision of analysis results was investigated, and the optimal particle size range was 120-150 mesh (0.121-0.104 mm).The sample mass test was also conducted, and it was found that 0.02 g of sample was optical.Moreover, the effect of analytical power and flux was studied.It was found the optical power was 5 000 W with the working current of pulse furnace at least 1 080 A.The sample could be completely fused and released completely when it was packaged with nickel foil as flux.The reference material of high-oxygen iron powder JK47 (w(O)=1.09%) with similar oxygen content in sample was selected to prepare the calibration curve with different sample mass.The correlation coefficient of curve was 0.995 1.The determination range of method was 0.2%-10%, and the low limit of determination was 0.000 41%.The precision test of silicon-calcium alloy was performed, and the relative standard deviation (RSD) was about 1%, which could meet the production requirements.The recovery test was conducted with high-purity SiO2 and CaO.The recoveries were between 95% and 105%.