In order to achieve decarburization and manganese retention simultaneously, CO2 was introduced in the smelting process of high-Mn twinning-induced plasticity (TWIP) steel. The effect of CO2 and O2 mixed injection on the decarburization and manganese retention was carried out based on the thermodynamics calculation and experimental research. The calculation results showed that the evaporation loss of manganese decreased dramatically with increasing CO2 blowing proportion, from the value close to 38 kg/t at pure O2 blowing to the value close to 4.4 kg/t at 40 vol pct CO2 proportion. The oxidation loss of manganese decreased from 70.5 to 41.7 kg/t when the CO2 blowing proportion increased from 0 to 40 vol pct. Additionally, the obtained data of the present experiments indicated that the introduction of CO2 could significantly lower the manganese loss and improve decarburization efficiency. The decarburization and manganese retention could be achieved simultaneously by replacing the partial oxygen with CO2 in the injected gas. Moreover, increasing the flow rate of the CO2-O2 gas mixture and increasing the melt temperature would improve decarburization efficiency but deteriorate the retention of manganese in the meantime.

中文翻译：

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CO2和O2混合注入对高锰孪生塑性钢脱碳和锰保留的影响

为了同时实现脱碳和保锰，在高锰孪晶诱导塑性（TWIP）钢的冶炼过程中引入了CO2。基于热力学计算和实验研究，研究了CO2和O2混合注入对脱碳和锰截留的影响。计算结果表明，随着 CO2 吹入比例的增加，锰的蒸发损失急剧下降，从纯 O2 吹入时接近 38 kg/t 的值下降到在 40 vol pct CO2 比例下接近 4.4 kg/t 的值。当 CO2 吹入比例从 0 增加到 40 vol pct 时，锰的氧化损失从 70.5 kg/t 减少到 41.7 kg/t。此外，本实验所得数据表明，CO2的引入可以显着降低锰损失，提高脱碳效率。通过用注入气体中的 CO2 代替部分氧气，可以同时实现脱碳和锰保留。此外，增加CO2-O2气体混合物的流量和提高熔体温度会提高脱碳效率，但同时会降低锰的保留率。