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液态合金的质量是影响铸件质量的最直接和最主要的因素之一,在炉前对液态合金的质量进行快速检验对于铸造生产有着重要意义。表面张力是液态合金的基本物理属性,它在许多方面反映了液态合金的特点,并对铸造过程产生重要影响。本文论述了铸造检测技术研究与应用的现状及发展趋势,对铁水质量炉前快速检验的各种方法做了详尽全面的评价,并经过理论分析后认为在一定条件下可以通过测定铁水的表面张力来迅速预测其凝固后的石墨形态并进而预测铸件质量。在对现有的液态合金表面张力测定方法进行对比分析之后,本文提出了一种有别于气泡最大压力法的快速测定表面张力的新方法———气泡幅频当量法,通过测定在规定时间内连续逸出的气泡内压力变化的幅值和气泡个数来反映表面张力的大小,从而使测试时间大大缩短。据此原理我们对常温液体进行了模拟试验,并在此基础上研制了一套便携式的液态合金表面张力快速电测装置。该装置以8098单片计算机为核心,配以高精度微差压传感器及快换式耐高温探头而组成。利用此装置还首次实现了毛细管内径的电测量,使测试过程大为简化。经过实验证明,该装置具有分辨率高、测试速度快(仅需10s钟)、测试精度高、操作方便、工作稳定等特点,配以实用的数学模型后,不仅可以完成对常温液体?
The quality of liquid alloy is one of the most direct and important factors affecting the quality of castings. The rapid inspection of the quality of liquid alloy in front of the furnace is of great significance to the foundry production. Surface tension is the basic physical property of liquid alloys, which in many ways reflects the characteristics of liquid alloys and has a significant impact on the casting process. In this paper, the status quo and development trend of research and application of foundry testing technology are discussed. Various methods of rapid testing of molten iron quality in furnace are comprehensively evaluated. After theoretical analysis, it is considered that under certain conditions, the surface tension To quickly predict the solidified graphite morphology and then predict the quality of castings. After comparing the existing methods for measuring the surface tension of liquid alloys, a new method of rapid determination of surface tension, which is different from the maximum pressure method of bubble, is proposed in this paper. The bubble amplitude-frequency equivalent method, Within the continuous escape within the bubble pressure changes in the amplitude and the number of bubbles to reflect the size of the surface tension, so that the test time is greatly reduced. Based on this principle, we simulate the liquid at room temperature, and on this basis, we developed a set of portable liquid alloy rapid surface tension measuring device. The device to 8098 single-chip computer as the core, together with high-precision differential pressure sensor and quick-change high temperature probe and composition. Using this device for the first time also achieved the electrical measurement of the capillary diameter, the test process is greatly simplified. The experiment proved that the device has the characteristics of high resolution, fast test speed (only 10s), high test accuracy, easy operation and stable work. With the practical mathematical model, it can not only accomplish the normal temperature liquid?