工程科学学报，第38卷，第6期：780-786,2016年6月 Chinese Journal of Engineering,Vol.38,No.6:780-786,June 2016 DOI:10.13374/j.issn2095-9389.2016.06.006:http://journals.ustb.edu.cn 低氧特殊钢中大尺寸DS类夹杂物生成机理 姜敏，王昆鹏，侯泽旺，王新华 北京科技大学治金与生态工程学院，北京100083 ☒通信作者，E-mail:jiangmin@ustb.cd.cn 摘要为了探讨低氧特殊钢中大尺寸DS类夹杂物的生成机理，通过ASPEX PSEM explor©r自动扫描电镜对比分析国内外 低氧特殊钢试样中夹杂物特征（国内、外试样各两个），发现国内试样中夹杂物平均尺寸大于国外试样，夹杂物的最大尺寸则 数倍于国外试样：国内试样中夹杂物的最大尺寸分别为24.9和13.1m,国外试样分别为7.6和7.5μm.对比国内外特钢试 样中大尺寸与小尺寸夹杂物可发现二者成分基本相同，推断大尺寸DS类夹杂物可能是细小夹杂物碰撞长大而形成.通过分 析大尺寸夹杂物的可能来源，在实验室通过高温共聚焦激光扫描显微镜观察夹杂物在钢中固/液相界面处的行为.结果发 现，总氧降低至7×106时，尺寸5μm以下的微细夹杂物可被固/液相界面所捕捉，并在固/液相界面处发生碰撞、聚集、长大 而生成大尺寸(>12μum)DS类夹杂物. 关键词特殊钢：夹杂物：尺寸：生成机理 分类号TF764 Formation mechanism of oversized DS-type inclusions in low oxygen special steel JIANG Min,WANG Kun-peng,HOU Ze-ang,WANG Xin-hua School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:jiangmin@ustb.edu.cn ABSTRACT To investigate the generation mechanism of oversized DS-type inclusions in low oxygen special steel,a comparative analysis of inclusions was performed on overseas and domestic special steel samples by the automatic secondary electron microscopy ASPEX PSEM explorer.Both the average size and maximum size of inclusions are larger in domestic samples than overseas samples. Particularly,the maximum size of inclusions in domestic samples is several times that in overseas steel samples:24.9 and 13.I um in domestic samples and 7.6 and 7.5um in overseas samples,respectively.Based on the chemical composition analysis of inclusions in domestic samples,it is found that the oversized inclusions and smaller inclusions have similar compositions.Therefore,the detected DS-type inclusions are endogenous but not exogenous,which can be produced by collisions among inclusion particles.To further study the possible origins of the oversized DS-type inclusions,in-situ observation on the behaviors of inclusions at the solid/liquid interface in low oxygen special steel show that tiny inclusions less than 5 um can be easily and stably captured by the solid/liquid interface with a total oxygen content of 7x10.Moreover,collisions,agglomeration/coalescence and growth of inclusions captured by the solid/ liquid interface result in the formation of much larger size DS-type inclusions over 12 pm KEY WORDS special steel;inclusions;size:formation mechanisms 我国汽车等行业需要大量轴承、齿轮、弹簧、曲轴因习，而夹杂物的有害程度与其数量、尺寸、变形性 等高品质特殊钢.这些零部件服役时常常发生疲劳破能、在钢中的位置等因素密切相关4.围绕夹杂物控 坏.许多研究表明，夹杂物是钢材疲劳破坏的主要诱制，目前主要有两种典型炼钢工艺.第1种工艺强调 收稿日期：2015-06-24 基金项目：国家自然科学基金资助项目51304013)：国家重点基础研究发展规划资助项目(2010CB630806)工程科学学报，第 38 卷，第 6 期: 780--786，2016 年 6 月 Chinese Journal of Engineering，Vol． 38，No． 6: 780--786，June 2016 DOI: 10． 13374 /j． issn2095--9389． 2016． 06． 006; http: / /journals． ustb． edu． cn 低氧特殊钢中大尺寸 DS 类夹杂物生成机理 姜 敏，王昆鹏，侯泽旺，王新华 北京科技大学冶金与生态工程学院，北京 100083  通信作者，E-mail: jiangmin@ ustb． edu． cn 摘 要 为了探讨低氧特殊钢中大尺寸 DS 类夹杂物的生成机理，通过 ASPEX PSEM explorer 自动扫描电镜对比分析国内外 低氧特殊钢试样中夹杂物特征( 国内、外试样各两个) ，发现国内试样中夹杂物平均尺寸大于国外试样，夹杂物的最大尺寸则 数倍于国外试样: 国内试样中夹杂物的最大尺寸分别为 24. 9 和 13. 1 μm，国外试样分别为 7. 6 和 7. 5 μm． 对比国内外特钢试 样中大尺寸与小尺寸夹杂物可发现二者成分基本相同，推断大尺寸 DS 类夹杂物可能是细小夹杂物碰撞长大而形成． 通过分 析大尺寸夹杂物的可能来源，在实验室通过高温共聚焦激光扫描显微镜观察夹杂物在钢中固 /液相界面处的行为． 结果发 现，总氧降低至 7 × 10 － 6时，尺寸 5 μm 以下的微细夹杂物可被固/液相界面所捕捉，并在固/液相界面处发生碰撞、聚集、长大 而生成大尺寸( ＞ 12 μm) DS 类夹杂物． 关键词 特殊钢; 夹杂物; 尺寸; 生成机理 分类号 TF764 Formation mechanism of oversized DS-type inclusions in low oxygen special steel JIANG Min ，WANG Kun-peng，HOU Ze-wang，WANG Xin-hua School of Metallurgical and Ecological Engineering，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: jiangmin@ ustb． edu． cn ABSTＲACT To investigate the generation mechanism of oversized DS-type inclusions in low oxygen special steel，a comparative analysis of inclusions was performed on overseas and domestic special steel samples by the automatic secondary electron microscopy ASPEX PSEM explorer． Both the average size and maximum size of inclusions are larger in domestic samples than overseas samples． Particularly，the maximum size of inclusions in domestic samples is several times that in overseas steel samples: 24. 9 and 13. 1 μm in domestic samples and 7. 6 and 7. 5 μm in overseas samples，respectively． Based on the chemical composition analysis of inclusions in domestic samples，it is found that the oversized inclusions and smaller inclusions have similar compositions． Therefore，the detected DS-type inclusions are endogenous but not exogenous，which can be produced by collisions among inclusion particles． To further study the possible origins of the oversized DS-type inclusions，in-situ observation on the behaviors of inclusions at the solid/liquid interface in low oxygen special steel show that tiny inclusions less than 5 μm can be easily and stably captured by the solid/liquid interface with a total oxygen content of 7 × 10 － 6 ． Moreover，collisions，agglomeration/coalescence and growth of inclusions captured by the solid/ liquid interface result in the formation of much larger size DS-type inclusions over 12 μm． KEY WOＲDS special steel; inclusions; size; formation mechanisms 收稿日期: 2015--06--24 基金项目: 国家自然科学基金资助项目 51304013) ; 国家重点基础研究发展规划资助项目( 2010CB630806) 我国汽车等行业需要大量轴承、齿轮、弹簧、曲轴 等高品质特殊钢． 这些零部件服役时常常发生疲劳破 坏． 许多研究表明，夹杂物是钢材疲劳破坏的主要诱 因［1--3］，而夹杂物的有害程度与其数量、尺寸、变形性 能、在钢中的位置等因素密切相关［4--6］． 围绕夹杂物控 制，目前主要有两种典型炼钢工艺． 第 1 种工艺强调