高温合金母合金真空冶炼中炉前快速分析的取制样方法探讨

高温合金母合金的成分范围控制较窄,应用综合检测手段,建立了高温合金母合金中主量、微量及痕量元素的炉前快速分析方法。使用30 mm的铝刚玉材质取样杯,在真空感应炉中采用二次浸没法取高温合金母合金熔液,凝固后快速冷却完成取样。在样品的尾部切割厚约8 mm的第1试样,用于辉光放电质谱仪(GDMS)测试其痕量元素含量;在剩下的样品上再切割厚约5 mm第2试样片,并切割成宽约5 mm、长30 mm的长条,经打磨后剪成质量为0.5~1.0 g的颗粒,丙酮清洗后用于碳、硫和氧、氮、氢测试;在剩余部分样品上继续切割厚约8 mm的第3试样,采用X射线荧光光谱仪(XRF)测试主量元素含量,然后使用火花放电原子发射光谱仪测试硼元素含量;最后利用实验室数据对接系统汇总检测数据,将检测结果快速传输给冶炼控制室。实验研究了取样杯内直径尺寸、热处理温度和浸没次数对炉前样内部质量的影响,同时考察了取样杯材质对炉前样品中杂质元素的影响以及不同元素在炉前样柱体分布情况,通过制样方法和仪器设备选择优化测试时间,实现了在25 min内完成40余种主量、微量以及痕量元素的炉前快速分析。方法在高温合金母合金冶炼中得到了应用,为有效控制其主量元素以及高温合金纯净化提供准确数据。

Discussion on method of sampling and preparation for bath rapid analysis during vacuum melting of master superalloy

The composition range of master superalloy was narrow.A bath rapid analysis method of the main, micro and trace elements in master superalloy was established by the means of comprehensive detection. The master superalloy melt was sampled in the vacuum induction furnace by secondary immersion method with the aluminum corundum sampling cup (30 mm). The sampling was completed after solidification and quick cooling. The first specimen with a thickness about 8 mm was cut from the tail of the on-the-spot sample to determine the contents of trace elements by glow discharge mass spectrometer (GDMS). The second specimen with a thickness about 5 mm was cut from the remaining sample, and then cut into a strip with a width about 5 mm and length of 30 mm. The strip was polished and then cut into particles with the mass of 0.5-1.0 g. After cleaning with acetone, the particles were used for the determination of carbon, sulfur, oxygen, nitrogen and hydrogen. The third specimen with a thickness about 8 mm was sequentially cut from the remaining sample for the testing of main elements by X-ray fluorescence spectrometer (XRF). Then the content of boron was determined by spark discharge atomic emission spectrometer. Finally, the test results were summarized with the laboratory data docking system and then rapidly transmitted to the smelting control room. The influence of sampling cup internal diameter, heat treatment temperature and immersion times on the internal quality of the on-the-spot sample was investigated. Meanwhile, the influence of sampling cup material on the impurity elements in the on-the-spot sample and the distribution of different elements in the on-the-spot sample column was investigated. The testing time was optimized by selecting the sample preparation method and equipment. This analysis method realized the rapid analysis of more than 40 major, trace and trace elements in the high-temperature master superalloy within 25 minutes. The proposed method had been applied in the smelting of master superalloy, and provided accurate data for the effective control of the main elements as well as the purification of master superalloy.