精炼渣对钢中钛含量和洁净度的影响  

Effect of refining slag on Ti content and cleanliness of steel

作　　者：张蓬朝 李光强 胡可[3] 朱丽琴 刘畅 刘昱 ZHANG Pengzhao;LI Guangqiang;HU Ke;ZHU Liqin;LIU Chang;LIU Yu(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)

机构地区：[1]武汉科技大学耐火材料与冶金省部共建国家重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [3]武汉科技大学钢铁冶金新工艺湖北省重点实验室,湖北武汉430081

出　　处：《钢铁》2025年第2期67-75,93,共10页Iron and Steel

基　　金：国家自然科学基金资助项目(52374309,52004189);湖北省自然科学基金资助项目(2022BAA021);中国博士后科学基金资助项目(2022M721109,2023T160210);青年人才托举工程资助项目(2022QNRC001)。

摘　　要：轴承是各类机械装备转动部位最关键的基础件之一,工作部位多处于主机的心脏和关节等要害处,因此轴承的质量和疲劳寿命对于主体装备的性能和可靠性至关重要。随着轴承钢总氧含量的降低,钢中氧化物夹杂的尺寸和数量得到了有效控制,TiN夹杂对轴承钢疲劳寿命的影响开始凸显,因而轴承钢对钛含量有着严格的控制要求。相比于原料和合金中钛含量控制,精炼过程渣-钢反应实现轴承钢钛含量控制更具成本优势。基于CaO-SiO_(2)-Al_(2)O_(3)-0.05%TiO_(2)-5%MgO(质量分数)精炼渣与轴承钢反应的热力学计算和渣的液相线温度范围进行了轴承钢超低钛含量控制的精炼渣成分设计。通过渣-钢反应考察了精炼渣碱度和渣中Al_(2)O_(3)含量对钢中钛和铝含量、TiN尺寸分布和钢液洁净度的影响。结果表明,精炼渣碱度为2~4,Al_(2)O_(3)质量分数控制为25%~58%,可以有效地控制钢中钛和铝含量[w([Ti])<0.0012%、w([Al])<0.0150%]。随着精炼渣碱度的降低,钢中钛和铝含量降低,碱度为3的精炼渣处理的钢中钛和铝含量均满足预期要求,TiN的长大时间短,低碱度精炼渣有利于钢中TiN夹杂的控制,证明了渣系设计的可行性。随着精炼渣碱度增加、Al_(2)O_(3)含量的降低,钢中夹杂物数量密度和平均尺寸均减小,这与钢中氧含量的变化趋势一致。相同碱度的精炼渣,随着钢中Al_(2)O_(3)含量的降低,炉渣吸收固体夹杂物的能力提高,钢液具有更高的洁净度。48.71%CaO-16.24%SiO_(2)-30%Al_(2)O_(3)-0.05%TiO_(2)-5%MgO(质量分数)精炼渣能够有效地实现钢中低Ti含量和TiN夹杂物的控制,且处理后的钢液具有更高的洁净度。Bearings are one of the most critical foundational components in the rotating parts of various mechanical equipment.As they are often used at key points such as the heart and joints of the main machine,the quality and fatigue life of the bearings are crucial to the overall performance and reliability of the primary equipment.As the total oxygen content in bearing steel decreases,the size and number of oxide inclusions in the steel are effectively controlled.Consequently,the impact of TiN inclusions on the fatigue life of bearing steel becomes more pronounced,leading to stringent control requirements for Ti content in bearing steel.Compared to controlling Ti content through raw materials and alloys,achieving low Ti content in bearing steel through slag-steel reactions during the refining process offers a more cost-effective solution.Based on thermodynamic calculations and the liquidus temperature of slag,the composition range of CaO-SiO_(2)-Al_(2)O_(3)-0.05%TiO_(2)-5%MgO(mass fraction)refining slag to control ultralow Ti content in bearing steel was studied.The effects of refining slag basicity and Al_(2)O_(3) content in the slag on the Ti and Al contents in the steel,TiN size distribution,and steel cleanliness was investigated by slag-steel reaction.The results indicate that 25%-58%Al_(2)O_(3) containing slag with the basicity of 2-4 can effectively control the Ti and Al contents in the steel[w([Ti])<0.0012%、w([Al])<0.0150%].As the basicity of the refining slag decreases,the Ti and Al contents in the steel decrease,and the slag with the basicity of 3 meets the expected requirements for Ti and Al contents.The low-basicity refining slag is beneficial for controlling TiN inclusions in steel,proving the feasibility of the slag design.As the basicity of the refining slag increases and the Al_(2)O_(3) content decreases,the number density and average size of inclusions in the steel decrease,consistent with the trend in the oxygen content.For refining slags with the same basicity,as the Al_(2)O_(3) content in the steel

关 键 词：轴承钢 钛含量 渣-钢反应 热力学 洁净度 精炼渣 夹杂物 碱度 

分 类 号：TF769[冶金工程—钢铁冶金]