硫含量对无取向硅钢夹杂物特性及磁性能的影响  

Effect of sulfur content on inclusion characteristics and magnetic properties of non-oriented silicon steel

作　　者：郑晓娜 朱诚意 刘玉龙[1,3,4] 朱榕 李光强 ZHENG Xiaona;ZHU Chengyi;LIU Yulong;ZHU Rong;LI Guangqiang(The State Key Laboratory of Refractories and Metallurgy,Wuhan 430081,Hubei,China;Hubei Collaborative Innovation Center for Advanced Steel,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]省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [2]武汉科技大学高性能钢铁材料及其应用省部共建协同创新中心,湖北武汉430081 [3]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 [4]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：《钢铁研究学报》2024年第11期1429-1439,共11页Journal of Iron and Steel Research

基　　金：钢铁冶金及资源利用省部共建教育部重点实验室开放基金资助项目(FMRUlab2023244)。

摘　　要：无取向硅钢中微米级和纳米级硫化物对钢的磁性都有较大的影响。为了掌握钢液深度脱硫对成品无取向硅钢夹杂物特性和磁性能的影响机制,借助SEM/TEM-EDS和图像分析软件,研究了硫含量不同的成品钢中夹杂物和析出相的组成、数量和尺寸变化,并检测了成品的磁性能。结果表明,实验钢中主要的夹杂物是单独的AlN、(Al, Si)_(x)N_(y)、MnS及AlN/(Al, Si)_(x)N_(y)-MnS复合夹杂物,存在少量MgO·Al_(2)O_(3)为主的复合氧化物或氧化物-MnS的复合夹杂物和以Cu_(x)S和MnS-Cu_(x)S复合物为主的析出相。钢中硫含量降低,硫元素在凝固前沿的偏析减少,钢中氮-硫复合夹杂物数量减少。硫含量越低的试样,钢中铝和氮含量相对更高,氮化物数量增加。脱氧充分的实验钢中硫含量变化对钢中氧化物、硫化物、氧-硫复合夹杂物数量影响较小。在钢液凝固过程中,MnS的析出量随着钢中硫含量降低依次减少,改变了含MnS类夹杂物的析出数量和尺寸,导致夹杂物总量减少,夹杂物尺寸分布不均匀。MnS夹杂物含量的差异主要来源于钢液凝固分率高于0.7以后钢液中[S]在凝固前沿的偏析。当钢中的硫质量分数降低到15×10^(-4)%及以下后,硫元素在钢液凝固前沿的偏析差异很小。硫质量分数为10×10^(-4)%的钢中夹杂物和析出相的数量较少,主要为2.0μm左右的小夹杂物和平均尺寸为52 nm的细小析出物,对应的成品钢的磁性能最好,B_(50)=1.751 T,P_(1.5/50)=4.16 W/kg。钢中硫质量分数降低到5×10^(-4)%后,钢的铁损反而升高了0.27 W/kg,磁感减小了0.040 T,一定程度上与钢液深度脱硫导致钢中铝和氮含量及3μm以上夹杂物增加有关。冶炼工序过度降低无取向硅钢的硫含量反而劣化了钢的磁性能。The magnetic properties of non-oriented silicon steel are greatly affected by micrometer and nano-sized sulfide.The effect mechanism of deep desulfurization of liquid steel on the inclusion characteristics and magnetic properties of the finished non-oriented silicon steels was investigated.The composition,number,and size of inclusions and precipitatesin the finished non-oriented silicon steels with different sulfur contents were studied using SEM/TEM-EDS and image analysis software,and the magnetic properties of the finished steel were measured.The statistical results indicated that the main inclusions in the experimental steels are AlN,(Al,Si)_(x)N_(y),MnS,and AlN/(Al,Si)_(x)N_(y)-MnS composite inclusions.There are small amounts of composite oxides containing MgO·Al_(2)O_(3) or oxides-MnS composite inclusions.The precipitates are mainly composed of Cu_(x)S and MnS+Cu_(x)S composite precipitates.The segregation of[S]at the solidification front decreases with the decrease in sulfur content,resulting in a decrease in the number of nitrogen sulfides in the steel.The research results indicate that the lower the sulfur content is in the steel,the higher the residual nitrogen content is in the steel,and the number density of nitrides increases.The change of sulfur content has little effect on the number of oxides,sulfides,and oxysulphides in the fully deoxygenated steels.During the solidification process of the molten steel,the precipitation amount of MnS decreases in sequence with the decrease of sulfur content,so the precipitation amounts and size of inclusions containing MnS are changed,resulting in a decrease in the total amount of inclusions and an inhomogeneous distribution of inclusion size.The difference of MnS-bearing inclusions precipitating mainly originates from the segregation difference of[S]until the solidification ratio of the liquid steel is higher than 0.7,and when the content of sulfur in the steel decreases to 15×10^(-4)%or less,the segregation difference of[S]at the solidification front is very s

关 键 词：无取向硅钢 硫含量 夹杂物 析出物 磁性能 

分 类 号：TG174[金属学及工艺—金属表面处理]