含铈耐热钢凝固过程中的夹杂物行为

建立了稀土耐热钢凝固过程中夹杂物析出与溶质元素微观偏析的耦合热力学模型，并通过工业试验与高温模拟实验验证了模型的准确性。利用该模型，依次考察了铈添加量，初始氧含量，初始硫含量对253MA耐热钢凝固过程中夹杂物析出行为的影响作用规律。在本模型条件下，随着铈添加量的增加，钢中的SiO2与MnS消失，且凝固过程中开始析出CeN；随着初始氧含量的增加，钢中开始析出Ce2O3，SiO2及MnS，其中SiO2与MnS在凝固过程中析出；随着初始硫含量的增加，钢中的Ce2O3消失，钢中开始析出Ce3S4与MnS，在凝固过程中析出的Ce3S4逐渐在液相线温度以上析出。研究工作对于稀土耐热钢连铸水口结瘤问题的解决具有理论指导意义。

Behavior of inclusions during solidification of heat-resistant steel containing cerium

A coupled thermodynamic model of inclusions precipitation and microsegregation of solute elements during solidification of heat-resistant steel containing cerium is achieved. Then the validation of this model is conducted through commercial test and physical simulation experiment at high temperature in laboratory. The effect of cerium adding, oxygen content and sulfur content on the inclusions behavior during solidification of 253MA steel is studied. The results are concluded as follows. As the increase of cerium adding, SiO2 and MnS disappear, and CeN begins to form during solidification. Ce2O3, SiO2 and MnS are formed as the oxygen content increases, and the latter two are precipitated during the solidification. As the sulfur content increases, Ce3S4 and MnS are formed while Ce2O3 disappears, and the precipitation temperature of Ce3S4 develops from liquid-solid area to above the liquidus. All the work will indicate the theoretical direction to solve nozzle clogging problem of heat-resistant steel containing rare earth elements.