Q345D钢中含钙类夹杂物的演变和生成机理分析  

Analysis of evolution and formation mechanism of calcium-containing inclusions of Q345D steel

作　　者：音正元 张立峰 李超 杨文[1] 任英[1] YIN Zheng-yuan;ZHANG Li-feng;LI Chao;YANG Wen;REN Ying(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;State Key Lab of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,Hebei,China;Technology Research Institute,HBIS Group,Shijiazhuang 050023,Hebei,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066044 [3]河钢集团钢研总院,河北石家庄050023

出　　处：《钢铁》2020年第11期47-56,共10页Iron and Steel

基　　金：国家自然科学基金资助项目(U1860206、51725402、51874031)。

摘　　要：通过工业实践研究Q345D钢生产过程含钙类夹杂物的演变和生成机理,并结合热力学计算研究了夹杂物凝固过程的转变机理。结果表明,钢中钙主要来源于VD真空冶炼和钙处理;真空前夹杂物CaO含量很低,破空后夹杂物CaO含量开始升高;之后由于钙处理,夹杂物CaO含量进一步升高。钢液冷却凝固过程中夹杂物发生明显转变,铸坯夹杂物中CaO含量明显降低,CaS含量显著升高,其结果与FactSage热力学计算结果一致。铸坯大尺寸含钙夹杂物主要分为钙铝酸盐、CaS包裹钙铝酸盐、CaS包裹钙铝酸盐且中间析出尖晶石、CaS和Al2O3黏结型及CaS和尖晶石黏结型;统计表明,铸坯中夹杂物尺寸越大,夹杂物中CaO含量越高,大尺寸夹杂物中CaS含量极低。The formation mechanism of calcium-containing inclusions during the production of Q345D steel was investigated through industrial trials.Thermodynamic calculations are used to study the transformation mechanism of inclusions during solidification.The results showed that calcium in steel mainly comes from the VD vacuum and calcium treatment.The CaO content of inclusions before the vacuum is very low.However,after the vacuum break,the CaO content of inclusions increased due to entrainment.After calcium treatment,the CaO content of inclusions further increased.The composition of the inclusions changed significantly during solidification.The content of CaO in inclusions of slab decreased significantly,and the content of CaS increased significantly,which is consistent with the thermodynamic calculation results.The large-sized calcium-containing inclusions in the slab are mainly divided into calcium aluminate,calcium aluminate surrounded by CaS,calcium aluminate with spinel surrounded by CaS,CaS,and Al2O3 bonding type,and CaS and spinel bonding type.The larger the inclusion size is,the higher the content of CaO is.The content of CaS in large-size inclusions is extremely low.

关 键 词：Q345D 含钙夹杂物 演变机理 卷渣 热力学计算 

分 类 号：TG142.33[一般工业技术—材料科学与工程]