取向硅钢凝固过程Mn、S、Al、N的热力学研究

Thermodynamic study on Mn, S,Al and N in the solidification process of grain oriented sillicon steel

采用热力学软件Thermo-Calc分析Mn、S、Al、N对TL(液相线温度)和TS(固相线温度)的影响以及在凝固过程中的偏析行为。结果表明:钢中Mn的质量分数从0增加到0.50%,TL略降低,TS先降低后增高;S从0增加到0.030%,TL降低1℃,TS约降低78℃;Al和N都从0增加到0.030%,几乎不影响TL和TS。成分固定时,MnS的析出使Mn从正偏析转变为负偏析,Mn主要形成了MnS相;S是比较强烈的正偏析元素,MnS相的析出也不能改变S的偏析特征;Al为负偏析元素;从1 490℃降低到约1 410℃的过程中N为正偏析元素,温度约低于1 410℃时为负偏析元素。

Thermo-Calc software is used to analyze the influence of Mn, S, Al and N elements on the difference between TL(liquidus temperature, ℃) and TS(solidus temperature, ℃) and the segregation behavior during solidification. The results show that the weight percent of Mn increase from zero to 0.030% in steel, TL slightly reduce, while TS decreases first and then increases. When S increases from zero to 0.030%, TL decreases by 1 ℃, TS decreases by 78 ℃. When Al and N increased from zero to 0.030%, it hardly affected TL and TS. When the composition is fixed, the precipitation of MnS changes Mn from positive segregation to negative segregation, and Mn mainly forms MnS phase. S is a relatively strong positive segregation element, and the precipitation of MnS phase cannot change this segregation behavior of S. Al is a negative segregation element. In the process of decreasing from 1 490 ℃ to 1 410 ℃, N is a positive segregation element, and when the temperature is lower than 1 410 ℃, N is a negative segregation element.