连铸中间包出口钢水浇注温度的连续测量传感器研究

The molten steel temperature, at the outlet of tundish, can most accurately represent the pouring temperature of the whole tundish. Molten steel flows from the tundish to mould and begins to solidify. The outlet of tundish is closest to where molten steel begins to solidify. The temperature at this location is the best point to control the temperature of continuous casting process. However, the outlet has a small space, fast speed flow of molten steel, and severe erosion, leading to that the temperature is difficult to be measured. The present method indirectly represents the pouring temperature of molten steel by measuring the temperature of other locations in tundish. It causes a deviation which has uncertain value. As a result, steel enterprises can only adopt more conservative control parameters such as superheat, water content and casting speed, which reduces the precision of solidification control and affects the quality of slabs..Therefore, this work is to develop a miniaturized blackbody cavity temperature sensor. It is combined with the stopper rod to measure the pouring temperature of molten steel at tundish outlet, without changing the flow control structure of stopper rod. The main research mainly solves the material and structure problems of the sensor: (1) In order to make the small sensor with the thin-walled structure, a new snesor material that has good erosion resistance will be investigated to solve the life problem of thin-walled sensor under the strong erosion condition. (2) The small sensor structure that builds a blackbody cavity will be investigated to achieve accurate temperature measurement in the small space. Based on the above researches, they will change the current situation that the pouring temperature of molten steel at tundish outlet is difficult to be measured directly.

中间包出口的钢水温度最能精准代表整个中间包的钢水浇注温度。钢水从中间包流入结晶器开始凝固，中间包出口离钢水开始凝固的位置最近，该处的温度是控制连铸工艺温度的最佳点。但中间包出口的空间小、钢水流速快、冲刷剧烈，测温困难。现有方法通过测量中间包其它位置温度，间接代表钢水浇注温度，存在偏差，且偏差具有一定不确定性。这导致钢铁企业只能采用更保守的过热度、水量、拉速等控制参数，降低了凝固控制精准度，影响铸坯质量。.为此，本项目提出研制一种小型化黑体空腔测温传感器复合于塞棒底端，在不改变塞棒控流结构的前提下，测量中间包出口的钢水浇注温度。主要研究解决传感器的材料与结构两方面问题：（1）为了以薄壁制作小型化传感器，研究抗冲刷的新型传感器材料，解决薄壁传感器在强冲刷侵蚀环境的寿命问题；（2）研究构建黑体空腔的小型化传感器结构，实现在小空间精确测温。通过研究，改变中间包出口钢水浇注温度难以直接测量的现状。

中间包出口钢水温度最能精准代表整个中间包的钢水浇注温度。钢水从中间包流入结晶器开始凝固，中间包出口离钢水开始凝固的位置最近，该处的温度是控制连铸工艺温度的最佳点。但中间包出口空间小、钢水流速快、冲刷剧烈，测温困难。现有方法通过测量中间包其它位置温度，间接代表钢水浇注温度，存在偏差，且偏差具有一定不确定性。这导致钢铁企业只能采用更保守的过热度、水量、拉速等控制参数，降低了凝固控制精准度，影响铸坯质量。.为此，本项目研究一种小型化黑体空腔测温传感器，复合于塞棒底端，测量中间包出口钢水浇注温度。主要从4个方面研究了传感器的实现：（1）小空间强冲刷条件下的传感器材料研究；（2）黑体空腔塞棒测温传感器的结构研究；（3）透气式塞棒测温传感器研究；（4）传感器的研制与工业试验。.通过本项目研究，研制了能连续测量连铸中间包出口钢水浇注温度的传感器，达到了如下性能指标：使用寿命满足24h的要求，测温精度：≤±3℃，传感器壁厚3-5mm。新型传感器已在4家钢厂连铸机的中间包上工业试验成功，在2家钢厂小批量试用，为钢厂揭开了浇注温度的神秘面纱。.钢厂试验反馈表明，新型传感器具有两方面显著效益：（1）将塞棒和测温传感器合二为一，降低原有钢水测温传感器和塞棒共同使用时成本约25%；（2）浇注温度正支撑钢厂进行更加精准的凝固控制，从而降低过热度冗余，提高产品质量。应用表明，过热度有望降低3-5℃，过热度降低1℃，吨钢成本降低约1元。综上所述，浇注温度测量对于钢厂而言具有重要经济价值和社会效益，得到钢厂认可。