稀土碳锰纯净钢中夹杂物形成与转化的热力学计算及观察分析

Thermodynamic Calculation on Precipitation and Transformation of Inclusions in High Purity Carbon-Manganese Steels with Rare Earths and Their Microstructure Analysis

用多相、多组元平衡的热力学计算方法,对稀土碳锰纯净钢中夹杂物的析出和转化进行了计算。结果表明,稀土元素能有效地变质Al2O3夹杂,在本实验所用材料的成分条件下,Al2O3完全消失的稀土含量为:1600℃时,La>0.009%,Ce>0.01%;1518℃时,La>0 012%,Ce>0 013%,稀土变质Al2O3的产物主要为RE2O2S。当La含量大于0.028%,Ce含量大于0.027%后,体系中将会有RES产生,但夹杂物仍然以RE2O2S为主。对试样的扫描电镜观察和分析证实了热力学计算的结果。

Thermodynamic calculation on balance of multi-phases and multi-components was used to analyze the precipitation and transformation of inclusions in high purity carbon-manganese steel with La or Ce. The result shows that on the condition of components of the material in this experiment, Al_2O_3 can be entirely replaced and RE_2O_2S mainly forms while content of rare earths meets the requirements as follows: La is more than 0.009% or Ce more than 0.010% at 1600 ℃, La is more than 0.012% or Ce more than 0.013% at 1518 ℃. While content of La is more than 0.028% or Ce more than 0.027%, there will be RES in the steels, however main form of inclusions is still RE_2O_2S. These results have been testified by observations of samples by SEM.