Study of the solidification behaviour of metallurgical slags using the Single Hot Thermocouple Technique
With the Single Hot Thermocouple Technique (SHTT) the solidification behaviour of metallurgical slags has been studied using the apparatus of the Freiberg University of Mining and Technology, Germany, in cooperation with the Federal University of Rio Grande do Sul, Brazil. With this technique, which is suitable to build TTT or CCT diagrams, the sample is put on a thermocouple tip and can be heated or cooled at very high rates (> 3000 °C/min) due to the low mass of the system. One advantage is to allow in situ observation of melting and solidification under various thermal conditions. The motivation for this work is to provide basic information related to crystallisation control, for the development of fluorine-free mould slags for continuous casting of steel. Slags in the systems CaO-Al2O3, CaO-SiO2, CaO-SiO2-TiO2, and CaO-SiO2-TiO2-Na2O were studied, analysing the kinetics of crystals growth and crystals morphology. Following findings are reported: (i) for the slag CS (％CaO/％SiO2 = 0.7) no crystal is observed during continuous cooling even to low cooling rates, but on the other hand intense crystallisation is obtained when increasing the temperature after reaching a particular range of lower temperatures; (ii) it was observed that the longer the duration of the superheating, the longer the incubation times for one slag CST (41％CaO, 29％SiO2, 30％TiO2) which has high liquidus temperature; (iii) the addition of Na2O into the CaO-SiO2-TiO2 slag system shortens intensely the crystals incubation times at TTT diagrams to the range of seconds. Therefore Na2O acts as crystallisation accelerator.
Single Hot Thermocouple Technique Metallurgical slags Fluorine-free mould fluxes Slab casting
Jeferson L. Klug R. Hagemann Nestor C. Heck Ant(o)nio C. F. Vilela Hans P. Heller Piotr R. Scheller
Federal University of Rio Grande do Sul, Brazil Freiberg University of Mining and Technology, German Freiberg University of Mining and Technology, Germany Federal University of Rio Grande do Sul, Brazil
国际会议
Ninth International Conference on Molten Slags,Fluxes and Salts(第九届国际熔渣、溶剂与熔盐学术会议 MOLTEN12)
北京
英文
1-15
2012-05-27（万方平台首次上网日期，不代表论文的发表时间）