高频燃烧红外吸收法测定镍基高温合金中碳的助熔剂影响探讨

对高频燃烧-红外吸收法测定镍基高温合金中碳的实验条件进行了探讨,并考察了助熔剂的种类、加入方式、用量以及样品称样量对测定的影响。实验表明:添加0.4 g铁助熔剂与1.2 g钨锡助熔剂于试样底部时,样品燃烧情况最佳;称取0.5 g试样,既能防止样品燃烧溢出,又能保证样品有代表性。方法的测定范围为0.000 5%～0.23%,测定下限为0.000 5%。采用实验方法分析普通精密铸造合金、变形高温合金、定向凝固高温合金等不同工艺制备的镍基高温合金以及其他镍基合金,测定值与认定值相符。将实验方法应用于镍基高温合金标准样品和实际样品中碳的测定,结果的相对标准偏差(RSD,n=8)为0.16%～3.3%。

Influence of flux on the determination of carbon in nickel-based superalloy by high frequency combustion infrared absorption method

The experimental conditions for the determination of carbon in nickel-based superalloy by high frequency combustion infrared absorption method were discussed. The effect of flux type, addition way, dosage and sampling mass on the determination was investigated. The results showed that the sample combustion was best when 0.4 g of iron flux and 1.2 g of tungsten-tin flux were added on the bottom of sample. For 0.5 g of sample, the combustion overflow could be prevented. Meanwhile, the sample representativeness could be guaranteed. The determination range of method was 0.000 5%-0.23%, and the low limit of determination was 0.000 5%. The proposed method was applied to the determination of nickel-based superalloys and other nickel-based alloys prepared by different processes, including normal precision casting alloy, wrought superalloy and controlled directional solidification high temperature alloy. The found results were consistent with the certified values. The proposed method was also applied to the determination of carbon in standard sample and actual sample of nickel-based superalloy. The relative standard deviations (RSD, n=8) were between 0.16% and 3.3%.