摘要
钢液真空循环脱气法(RH)精炼能够利用高真空和钢液循环流动有效脱气和去除夹杂物.同时,炼钢环境下CO2可与钢液中[C]反应生成CO提高搅拌强度.因此,本文提出将CO2作为RH提升气进行真空精炼.针对CO2在RH精炼过程的冶金反应行为特性,通过热力学理论分析了极限真空条件下CO2脱碳的有利条件及限度,同时搭建了CO2作RH提升气工业试验平台,通过工业试验对比研究了CO2/Ar分别作提升气时对钢液精炼过程的影响.结果表明,若单纯考虑CO2与碳反应,则当钢液中[C]低于1.8×10-6,CO2仍然具有氧化碳元素的能力.然而,CO2对钢液中碳铝元素存在选择性氧化,当铝含量低于一定程度时,CO2主要参与脱碳反应;反之,CO2则会造成一定铝损,因此若采用新工艺需考虑铝合金加入时机以及加入量.此外,CO2用作RH提升气可获得与Ar效果相当甚至更优的脱氢效果,喷吹同等量CO2并未造成钢液的大幅温降,因此CO2完全有潜力作为RH提升气,进而完成精炼.
Developing new technologies that can utilize CO2 as a resource or reduce CO2 emission is an urgent need in the iron and steel industry.The Ruhrstahl-Heraeus(RH)refining process can effectively remove gas and inclusions from molten steel by applying a high vacuum and intense circulation flow of the molten steel.Meanwhile,at the steelmaking temperature,CO2 can react with carbon in the molten steel to generate CO bubbles,and this enhances the molten bath stirring strength.Therefore,a technology involving the use of CO2 as the lifting gas in RH refining was proposed.To study the applicability of CO2 in RH refining,the favorable conditions and limits of CO2 decarburization under vacuum conditions were analyzed through thermodynamics.Meanwhile,an industrial test platform for CO2 as RH lifting gas was set up,and the effects of CO2/Ar as lifting gas on the refining process of molten steel were comparatively studied through industrial tests.The results show that if only the reaction between CO2 and carbon is considered,CO2 can still oxidize carbon elements when the carbon content is less than 1.8×10-6.However,CO2 selectively oxidizes carbon and aluminum in molten steel.When the aluminum content is below a certain level,CO2 mainly participates in a decarburization reaction;otherwise,CO2 will cause certain aluminum loss.Therefore,if the new process is adopted,the timing and amount of aluminum alloy addition should be considered.In addition,CO2 can be used as RH lifting gas to obtain a dehydrogenation effect equivalent to or even better than that of Ar.Meanwhile,injecting the same amount of CO2 did not cause a large temperature drop of molten steel;therefore,CO2 has the potential to be used as RH lifting gas to complete refining.
作者
魏光升
韩宝臣
朱荣
WEI Guang-sheng;HAN Bao-chen;ZHU Rong(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials,Beijing 100083,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2020年第2期203-208,共6页
Chinese Journal of Engineering
基金
中国博士后科学基金面上资助项目(2019M660459)
中央高校基本科研业务费资助项目(FRF-TP-19-031A1).
关键词
二氧化碳
RH精炼
脱碳反应
脱氢效果
钢液温降
carbon dioxide
RH refining
decarburization reaction
dehydrogenation effect
temperature drop
