A New Method for Sensing Pouring Temperature of Molten Steel in Tundish

Abstract

Pouring temperature of molten steel at the outlet of the tundish is the key parameter to control the solidification accurately. However, the stopper occupies the top of the outlet, leading to that the existing sensor cannot measure the molten steel temperature at the outlet. To solve the problem, this work develops a new small sensor installed at the bottom of the stopper, which combines the stopper and the temperature sensor into one. Mo-W-ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> cermet that has excellent corrosion resistance has been used to make a small sensor with a thin-walled structure of 5 mm thickness. To sense the pouring temperature independently, fast and accurately, the length/radius ratio of the small sensor should reach 13 to form a blackbody cavity approximately. According to the industrial test, the pouring temperature of molten steel is measured for the first time in the field of metallurgy. Meanwhile, a deviation (e.g., 8.2 °C or 1.4 °C) between the pouring temperature and the temperature measured by the existing sensor is found. As a result, based on the temperature measured by the existing sensor, the superheat of molten steel and the cooling water flow usually have enough margin for ensuring the safe operation of continuous casting, reducing the control accuracy of the solidification and increasing the risk of quality problems. Therefore, this work will be helpful to control the solidification more accurately, improving the product quality.