高频感应燃烧红外吸收法测定焊接药剂中硫含量

研究了高频感应燃烧红外吸收法测定焊剂、焊条药皮和药芯焊丝药粉等焊接药剂中硫含量的方法。最佳工作条件为先将0.1~0.15g样品加入预先放置有0.3~0.5g铁屑的瓷坩埚中,再覆盖0.2g锡粒和1.7g钨粒;采用0.3~0.5g钢铁有证标准样品建立校准曲线(助熔剂为0.2g锡粒-1.7g钨粒)。结果表明,方法的测定下限为0.005%(高纯氧气)至0.008%(普通氧气)。将实验方法用于不同硫含量的焊接药剂实际样品的分析,结果的相对标准偏差(RSD,n=6)不大于7%,加标回收率为83%~107%。采用焊剂及矿石标准样品进行准确度验证,测定值与认定值相符合。

Determination of sulfur in welding flux by high frequency induction combustion infrared absorption method

The determination method of sulfur in welding flux (including soldering flux, electrode covering and flux-cored wire powder) by high frequency induction combustion infrared absorption was studied. The optimum working conditions were obtained as below: 0.10-0.15g of sample was transferred into porcelain crucible containing 0.3-0.5g of scrap iron, and then covered by 0.2g of tin particles and 1.7g of tungsten particles; the standard curve was established using 0.3-0.5g of certified reference materials of steel (the flux was 0.2g of tin particles+1.7g of tungsten particles). The results showed that the lower determination limit of method was 0.005% (high-purity oxygen)-0.008% (normal oxygen). The experimental method was applied for the analysis of actual welding flux samples with different sulfur contents. The relative standard deviations (RSD, n=6) were less than 7%, and the recoveries were between 83% and 107%. The accuracy was verified using standard samples of welding flux and ore, and the found results were consistent with the certified values.