Abstract The mechanism of inclusions precipitation of the E690 offshore platform steel, with and without addition of yttrium, was studied using the thermodynamic calculation method. The results show that in the E690 steel in the absence of yttrium, the MnS inclusions were precipitated in the liquid phase at the solidification front. By adding the yttrium, MnS inclusions were replaced by spindle and spherical yttrium-containing oxide and sulfide complex inclusions, and the precipitation sequence of yttrium-containing inclusions in the liquid steel was Y2O3, Y2O2S, and YS. However, Y2S3 inclusions cannot be precipitated in the liquid steel under the experimental conditions. It was also found that Al2O3 inclusions can be formed in the liquid steel with and without addition of yttrium. The thermodynamic calculation results are in accordance with the experimental results.

中文翻译：

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添加钇对E690超高强海洋平台钢夹杂物析出行为的影响

摘要 采用热力学计算方法研究了E690海洋平台钢添加和不添加钇时夹杂物析出的机理。结果表明，在不含钇的 E690 钢中，MnS 夹杂物在凝固前沿在液相中析出。通过加入钇，MnS夹杂物被纺锤形和球形的含钇氧化物和硫化物复合夹杂物取代，钢液中含钇夹杂物的析出顺序为Y2O3、Y2O2S、YS。但在实验条件下，钢液中不能析出Y2S3夹杂物。还发现Al2O3夹杂物可以在添加和不添加钇的情况下在钢水中形成。