摘要
对超低碳IF钢钛合金化后的非金属夹杂物进行了分析,研究发现钛合金化后的夹杂物主要为Al_(2)O_(3)和Al-Ti-O夹杂物,没有发现纯TiO_(x)夹杂物.钢中生成的Al-Ti-O复合夹杂物从形貌上均可分为七种类型,四种具有Al_(2)O_(3)外层,另外三种无Al_(2)O_(3)外层.钛合金化后,钢中瞬态生成了大量无Al_(2)O_(3)外层的Al-Ti-O夹杂物,随后夹杂物表面生成Al_(2)O_(3)外层,导致有Al_(2)O_(3)外层的Al-Ti-O夹杂物数量比例逐渐增加至78.0%.热力学计算结果表明,随着钢中钛含量的增加,夹杂物的转变顺序为固态Al_(2)O_(3)→液态Al-Ti-O→固态Ti_(2)O_(3).确定了Al-Ti-O夹杂物的生成机理过程分为两步:精炼过程钛合金化后,当钢液局部区域的钛的质量分数高于0.42%时,[Ti]与钢液反应瞬态生成Al_(2)O_(3)-TiO_(x)或TiO_(x);随着精炼过程中钛元素的混匀,含TiO_(x)夹杂物被钢中[Al]还原,Al_(2)O_(3)-TiO_(x)和TiO_(x)夹杂物逐渐转变,在夹杂物表面生成Al_(2)O_(3).
In the current study, Al–Ti–O inclusions after Ti-alloyed in an ultra-low carbon IF steel were analyzed. It was found that Al–Ti–O inclusions were classified into seven types based on their morphologies, including four types with an Al2O3outer layer and the other three without the Al2O3outer layer. Approximately 78.0% of Al –Ti –O inclusions had an Al2O3outer layer. There was little separated TiOx inclusion detected in the steel. Without the consideration of the Al2O3layer of Al–Ti–O complex inclusions, the core of Al–Ti–O complex inclusions was generally similar to that without the Al2O3outer layer. Compared with the sample at 1 minute after the Ti addition, the number density of Al–Ti–O inclusions without an Al2O3outer layer in the sample at 4 minutes after the Ti addition decreased by 0.21 mm^(-2) , while the number density of Al–Ti–O inclusions with an Al2O3outer layer increased by 0.19 mm^(-2). After the titanium alloying process, a large number of Al–Ti–O inclusions without the Al_(2)O_(3) outer layer were transiently generated. Further, the Al2O3outer layer was formed on the surface of inclusions, leading to the increase of the percentage of Al–Ti–O inclusions with the Al2O3outer layer to 78.0%. Thermodynamic calculated results show that the evolution route of inclusions was solid Al2O3→ liquid Al–Ti–O → solid Ti2O3 with the increase of titanium content in the steel. The inclusion of Al2O3was the only stable phase in the liquid steel in equilibrium, while the high concentration of titanium in the local steel during the titanium alloying process led to the formation of titanium-containing oxides. When the oxygen content in the steel was lower than 0.03%, inclusions were mainly solid Al2O3. Inclusions containing TiOx were formed with oxygen content in the local steel exceeding 0.03% during the reoxidation process. The formation mechanism of Al–Ti–O inclusions was divided into two steps. After the titanium alloying process in the refining, when the local titanium content in the steel was higher than 0.42%, the [Ti] reacted with the molten steel to transiently form Al2O3–TiOx and TiOx. With the mixing of the titanium in the molten steel, the generated TiOx-containing oxides were reduced by [Al] in the steel. Inclusions of Al2O3-TiOx and TiOx gradually transformed to Al2O3on the surface.
作者
黄日康
姜仁波
周秋月
任英
姜东滨
张立峰
HUANG Ri-kang;JIANG Ren-bo;ZHOU Qiu-yue;REN Ying;JIANG Dong-bin;ZHANG Li-feng(Technology Center,Liuzhou Iron&Steel Co.,LTD.,Liuzhou 545002,China;Steelmaking Plant of Tangshan Stainless Steel Co.,Tangshan 063105,China;School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2023年第5期755-764,共10页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(U1860206,51725402)
河北省省级科技计划资助项目(20311004D,20591001D)。
关键词
超低碳钢
AlTiO夹杂物
形貌分类
生成机理
RH精炼
ultra low carbon steel
Al–Ti–O inclusions
morphology classification
formation mechanism
RH refining
