Industrial trials were performed to study the effect of calcium treatment on inclusions in non-oriented electrical steels. The evolution and characterization of inclusions in both molten steel and rolled steel were investigated, including a thermodynamic analysis using FactSage 7.1. In the Ca-treated steel, alumina inclusions were transformed into Al2O3-CaO-CaS, with a mass fraction of CaO that increased with increasing the Ca/S ratio. Inclusions of Al2O3-CaO-CaS were classified into wrapping and adhesion type according to their morphologies. Adhesion-type Al2O3-CaO-CaS inclusions were observed only in the steel with Ca/S > 0.84. The two types of Al2O3-CaO-CaS inclusions were transformed into Al2O3-CaS with distinctive morphologies. The mass fraction of Al2O3 and CaS in the inclusions was experimentally found to depend on the Ca/S ratio of the steel and confirmed by thermodynamic analysis. The two types of Al2O3-CaS inclusions could hardly be deformed during the hot-rolling process of the steel but showed different deformation behavior during the cold-rolling process of the steel. The component of CaS in the adhesion-type Al2O3-CaS inclusions was more easily separated from Al2O3 and formed a tail along the rolling direction of the steel, while only a little part of the CaS component broke off from the wrapping-type Al2O3-CaS inclusions.

中文翻译：

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Ca处理无取向电工钢中Al2O3-CaS夹杂物的形成及变形机制

进行了工业试验以研究钙处理对无取向电工钢中夹杂物的影响。研究了钢水和轧钢中夹杂物的演变和特征，包括使用 FactSage 7.1 进行的热力学分析。在 Ca 处理的钢中，氧化铝夹杂物转化为 Al2O3-CaO-CaS，CaO 的质量分数随着 Ca/S 比的增加而增加。Al2O3-CaO-CaS 夹杂物根据其形态分为包裹型和粘附型。仅在 Ca/S > 0.84 的钢中观察到粘附型 Al2O3-CaO-CaS 夹杂物。两种类型的 Al2O3-CaO-CaS 夹杂物转变为具有不同形态的 Al2O3-CaS。实验发现夹杂物中 Al2O3 和 CaS 的质量分数取决于钢的 Ca/S 比，并通过热力学分析证实。两种Al2O3-CaS夹杂物在钢的热轧过程中几乎不变形，但在钢的冷轧过程中表现出不同的变形行为。粘附型Al2O3-CaS夹杂物中的CaS成分更容易与Al2O3分离并沿轧钢方向形成尾部，而包裹型Al2O3-CaS夹杂物中的CaS成分仅有少部分脱离夹杂物。