工程科学学报.第41卷，第12期：1567-1574.2019年12月 Chinese Journal of Engineering,Vol.41,No.12:1567-1574,December 2019 D0L:10.13374.issn2095-9389.2018.12.18.004,http:/ournals.ustb.cdu.cn 202不锈钢中非金属夹杂物的形成机理 李璟宇”，成国光四，李六一2)，胡斌2)，徐昌松2，王贵民2) 1)北京科技大学钢铁治金新技术国家重点实验室，北京1000832)四川金广集团西南不锈钢有限责任公司，乐山106083 ☒通信作者，E-mail:chengguoguang@metall..ustb.edu.cn 摘要通过工业试验对202不锈钢进行系统取样，分析试样中夹杂物的变化特征，结合热力学计算，研究了202不锈钢中非 金属夹杂物的形成机理.在进行硅锰脱氧后，LF精炼过程中钢液内以球型Ca-Si-M-O夹杂物为主.对于硅锰脱氧钢，钢液 中残余铝质量分数为1×10时，可以扩大M-S-O相图的液相区，但铝质量分数超过3×105会导致钢中容易形成氧化铝夹 杂物并减小液相区.在连铸坯中以M-A-O类夹杂物为主，相较于LF精炼过程试样，连铸坯试样中夹杂物的MO和 Al2O3含量明显增加，Ca0和SiO2含量明显减小，夹杂物个数则由LF出钢试样的5.5mm2增加到1l.3mm2.结合热力学计 算发现，凝固过程中会有M-A-O夹杂物形成.这也使其成为连铸坯中主要的夹杂物类型 关键词不锈钢：硅锰脱氧：连铸：夹杂物：热力学计算 分类号TF764.1 Formation mechanism of non-metallic inclusions in 202 stainless steel LI Jing-yu,CHENG Guo-guang LI Liu-yi.HU Bin,XU Chang-song,WANG Gui-min 1)State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China 2)Southwest Stainless Steel Co.,Ltd.,Sichuan Jinguang Group,Leshan 106083,China Corresponding author,E-mail:chengguoguang @metall.ustb.edu.cn ABSTRACT Non-metallic inclusions generally deteriorate the quality of stainless steel products,such as skin laminations or line defects on the rolled strip in stainless steel.Thus,the formation mechanism of non-metallic inclusions in 202 stainless steel was investigated with industrial trials and thermodynamic calculation.Steel samples were analyzed by scanning electron microscopy and energy dispersive spectroscopy.Compositions of the steel samples were determined by inductively coupled plasma-optical emission spectrometer.After Si-Mn deoxidation,the main inclusions were spherical Ca-Si-Mn-O inclusions during LF refining process.The liquid phase region of the Mn-Si-O phase diagram was affected by the residual aluminum content in Si-Mn deoxidized stainless steel. 1x10mass fraction of aluminum in steel enlarged the liquid phase region of the Mn-Si-O phase diagram.However,more than 3x105 mass fraction of aluminum led to the formation of alumina inclusions and the reduction of the liquid phase region of the Mn-Si-O phase diagram.After the continuous casting process,the main inclusions in the steel were changed from Ca-Si-Mn-O to Mn-Al-O. Compared with the steel sample taken during the LF refining process,the MnO and Al2O3 content of inclusions in the continuous casting samples increased significantly,while the content of CaO and SiO,decreased significantly.At the same time,the amount of inclusions increased from 5.5 mm to 11.3 mm after continuous casting.Combined with thermodynamic calculations,it was found that Mn-Al-O inclusions were formed during solidification,which became the main type of inclusion after continuous casting.In addition, the effect of aluminum content on the formation of oxide inclusions during continuous casting was discussed.Thermodynamic calculation indicated that the alumina inclusions were formed in the steel containing more than 3x105 mass fraction of aluminum during continuous casting.High aluminum content promoted the formation of alumina and inhibited the formation of Mn-Al-O inclusions 收稿日期：2018-12-18 基金项目：国家自然科学基金资助项目（⑤1374020）：钢铁冶金新技术国家重点实验室资助项目(41618007)202 不锈钢中非金属夹杂物的形成机理 李璟宇1)，成国光1) 苣，李六一2)，胡    斌2)，徐昌松2)，王贵民2) 1) 北京科技大学钢铁冶金新技术国家重点实验室，北京 100083    2) 四川金广集团西南不锈钢有限责任公司，乐山 106083 苣通信作者，E-mail：chengguoguang@metall.ustb.edu.cn 摘    要    通过工业试验对 202 不锈钢进行系统取样，分析试样中夹杂物的变化特征，结合热力学计算，研究了 202 不锈钢中非 金属夹杂物的形成机理. 在进行硅锰脱氧后，LF 精炼过程中钢液内以球型 Ca−Si−Mn−O 夹杂物为主. 对于硅锰脱氧钢，钢液 中残余铝质量分数为 1×10−5 时，可以扩大 Mn−Si−O 相图的液相区，但铝质量分数超过 3×10−5 会导致钢中容易形成氧化铝夹 杂物并减小液相区. 在连铸坯中以 Mn−Al−O 类夹杂物为主，相较于 LF 精炼过程试样，连铸坯试样中夹杂物的 MnO 和 Al2O3 含量明显增加，CaO 和 SiO2 含量明显减小，夹杂物个数则由 LF 出钢试样的 5.5 mm−2 增加到 11.3 mm−2 . 结合热力学计 算发现，凝固过程中会有 Mn−Al−O 夹杂物形成，这也使其成为连铸坯中主要的夹杂物类型. 关键词    不锈钢；硅锰脱氧；连铸；夹杂物；热力学计算 分类号    TF764.1 Formation mechanism of non-metallic inclusions in 202 stainless steel LI Jing-yu1) ，CHENG Guo-guang1) 苣 ，LI Liu-yi2) ，HU Bin2) ，XU Chang-song2) ，WANG Gui-min2) 1) State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China 2) Southwest Stainless Steel Co., Ltd., Sichuan Jinguang Group, Leshan 106083, China 苣 Corresponding author, E-mail: chengguoguang@metall.ustb.edu.cn ABSTRACT    Non-metallic  inclusions  generally  deteriorate  the  quality  of  stainless  steel  products,  such  as  skin  laminations  or  line defects  on  the  rolled  strip  in  stainless  steel.  Thus,  the  formation  mechanism  of  non-metallic  inclusions  in  202  stainless  steel  was investigated  with  industrial  trials  and  thermodynamic  calculation.  Steel  samples  were  analyzed  by  scanning  electron  microscopy  and energy  dispersive  spectroscopy.  Compositions  of  the  steel  samples  were  determined  by  inductively  coupled  plasma-optical  emission spectrometer. After Si−Mn deoxidation, the main inclusions were spherical Ca−Si−Mn−O inclusions during LF refining process. The liquid phase region of the Mn−Si−O phase diagram was affected by the residual aluminum content in Si−Mn deoxidized stainless steel. 1×10−5 mass fraction of aluminum in steel enlarged the liquid phase region of the Mn−Si−O phase diagram. However, more than 3×10−5 mass fraction of aluminum led to the formation of alumina inclusions and the reduction of the liquid phase region of the Mn−Si−O phase diagram.  After  the  continuous  casting  process,  the  main  inclusions  in  the  steel  were  changed  from  Ca−Si−Mn−O  to  Mn−Al−O. Compared with the steel sample taken during the LF refining process, the MnO and Al2O3 content of inclusions in the continuous casting samples increased significantly, while the content of CaO and SiO2 decreased significantly. At the same time, the amount of inclusions increased  from  5.5  mm−2 to  11.3  mm−2 after  continuous  casting.  Combined  with  thermodynamic  calculations,  it  was  found  that Mn−Al−O inclusions were formed during solidification, which became the main type of inclusion after continuous casting. In addition, the  effect  of  aluminum  content  on  the  formation  of  oxide  inclusions  during  continuous  casting  was  discussed.  Thermodynamic calculation indicated that the alumina inclusions were formed in the steel containing more than 3×10−5 mass fraction of aluminum during continuous  casting.  High  aluminum  content  promoted  the  formation  of  alumina  and  inhibited  the  formation  of  Mn−Al−O  inclusions 收稿日期: 2018−12−18 基金项目: 国家自然科学基金资助项目 (51374020)；钢铁冶金新技术国家重点实验室资助项目 (41618007) 工程科学学报，第 41 卷，第 12 期：1567−1574，2019 年 12 月 Chinese Journal of Engineering, Vol. 41, No. 12: 1567−1574, December 2019 DOI：10.13374/j.issn2095-9389.2018.12.18.004; http://journals.ustb.edu.cn