第36卷第11期 北京科技大学学报 Vol.36 No.11 2014年11月 Journal of University of Science and Technology Beijing Now.2014 石油钻杆钢治炼过程中夹杂物的析出和衍变 隋亚飞，孙国栋，王灿国，郭 敏，张梅四 北京科技大学治金与生态工程学院，北京100083 ☒通信作者，E-mail:zhangmei@usth.cdu.cm 摘要系统分析了国内某钢厂复合脱氧工艺下CMo石油钻杆钢夹杂物在EAF-LF-VD-CC流程中的析晶和衍变规律.由 于铝酸盐的上浮，LF治炼前钢中TO]含量较低，治炼过程中氮含量逐渐升高.电镜下钢中大尺寸夹杂物(S0m左右)只出 现在LF-VD阶段，主要为低熔点的硅锰酸盐、包含NaO的混合物和含有少量C0的镁铝尖晶石，中间包阶段大尺寸夹杂物 完全消失.小尺寸夹杂物(<10μm)出现在精炼全过程中，主要成分是Mg、Al、Si和Ca的复合氧化物、CaS以及二者的复合 物，LF冶炼前到中间包阶段小尺寸夹杂物粒径相似，铸坯中其粒径稍微增加.随着精炼过程的进行，钢中小尺寸夹杂物的成 分逐渐向复合氧化物的低熔点区域转移，夹杂物中Ca0和Mg0含量存在竞争关系.铸坯中大型夹杂物(>100μm)包括卷渣 引起的复合夹杂，耐材剥落产生的Mg0C0夹杂和钢液内生的铝酸盐夹杂。内生铝酸盐与精炼过程中小尺寸夹杂物成分相 似，外层包覆CS,轧制过程中容易破碎成链状引发钻杆钢裂纹.建议适当延长VD处理后钢液的镇静时间，以去除钢中大型 铝酸盐夹杂，提高钻杆钢质量. 关键词钻杆；炼钢：非金属夹杂物：析品；衍变 分类号TF701.1 Inclusion formation and evolution in steelmaking process for drill pipes SUl Ya-fei,SUN Guo-dong,WANG Can-guo,GUO Min,ZHANG Mei School of Metallurgical and Ecological Engineering.University of Science and Technology Beijing,Beijing 100083.China Corresponding author,E-mail:zhangmei@ustb.edu.cn ABSTRACT The crystallization and evolution of non-metallic inclusions in CrMo drill pipe steel refined with a complex deoxidizer were investigated for the EAF-LF-VD-CC process flow of a domestic steel plant.As a result of aluminates floating,lower T[O]con- tent in the steel before the LF refining was shown,while nitrogen content in the steel gradually increased during the whole flow.Large size inclusions (about 50 m),namely,silicic manganates with low melting point,complexes with NaO and magnesium aluminate spinels with a little Cao,appeared at the LF-VD stage and disappeared completely after the tundish process.Small size inclusions (<10 um)could be found during the whole refining flow.Their size at different refining stages was similar to each other,while smal- ler than that of the casting blank.The small size inclusions were complex oxides which consist of Mg,Al,Si,Ca and CaS respectively. The composition of the small size inclusions gradually moved to the liquid phase region during the smelting flow,and competition exis- ted between CaO and Mgo contents in these inclusions.Macro inclusions (>100um)in the casting blank included complex inclusions caused by entrapped slag,Mgo-Cao inclusions from refractories and endogenous aluminate inclusions coated by a Cas layer,whose composition was similar to small size inclusions in the smelting processes.The macro aluminate inclusions were easily broken into chain and further resulted in cracks in the steel during the rolling process.Hence,it is suggested to prolong the steel standing time after the VD operation to remove detrimental aluminate inclusions. KEY WORDS drill pile:steelmaking:non-metallic inclusions:crystallization:evolution 石油钻杆是钻井时用于传递动力和输送泥浆的主要工具，需承受各种复杂交变的载荷和腐蚀性工 收稿日期：2013-12-一7 基金项目：国家自然科学基金资助项目(51372019,51074009,50874013)：国家高技术研究发展计划资助项目(2013AA032003) DOI:10.13374/j.issn1001-053x.2014.11.006:http://journals.ustb.edu.cn第 36 卷 第 11 期 2014 年 11 月 北京科技大学学报 Journal of University of Science and Technology Beijing Vol． 36 No． 11 Nov． 2014 石油钻杆钢冶炼过程中夹杂物的析出和衍变 隋亚飞，孙国栋，王灿国，郭 敏，张 梅 北京科技大学冶金与生态工程学院，北京 100083  通信作者，E-mail: zhangmei@ ustb． edu． cn 摘 要 系统分析了国内某钢厂复合脱氧工艺下 CrMo 石油钻杆钢夹杂物在 EAF--LF--VD--CC 流程中的析晶和衍变规律． 由 于铝酸盐的上浮，LF 冶炼前钢中 T［O］含量较低，冶炼过程中氮含量逐渐升高． 电镜下钢中大尺寸夹杂物( 50 μm 左右) 只出 现在 LF--VD 阶段，主要为低熔点的硅锰酸盐、包含 Na2O 的混合物和含有少量 CaO 的镁铝尖晶石，中间包阶段大尺寸夹杂物 完全消失． 小尺寸夹杂物( ＜ 10 μm) 出现在精炼全过程中，主要成分是 Mg、Al、Si 和 Ca 的复合氧化物、CaS 以及二者的复合 物，LF 冶炼前到中间包阶段小尺寸夹杂物粒径相似，铸坯中其粒径稍微增加． 随着精炼过程的进行，钢中小尺寸夹杂物的成 分逐渐向复合氧化物的低熔点区域转移，夹杂物中 CaO 和 MgO 含量存在竞争关系． 铸坯中大型夹杂物( ＞ 100 μm) 包括卷渣 引起的复合夹杂，耐材剥落产生的 MgO--CaO 夹杂和钢液内生的铝酸盐夹杂． 内生铝酸盐与精炼过程中小尺寸夹杂物成分相 似，外层包覆 CaS，轧制过程中容易破碎成链状引发钻杆钢裂纹． 建议适当延长 VD 处理后钢液的镇静时间，以去除钢中大型 铝酸盐夹杂，提高钻杆钢质量． 关键词 钻杆; 炼钢; 非金属夹杂物; 析晶; 衍变 分类号 TF 701. 1 Inclusion formation and evolution in steelmaking process for drill pipes SUI Ya-fei，SUN Guo-dong，WANG Can-guo，GUO Min，ZHANG Mei School of Metallurgical and Ecological Engineering，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: zhangmei@ ustb． edu． cn ABSTＲACT The crystallization and evolution of non-metallic inclusions in CrMo drill pipe steel refined with a complex deoxidizer were investigated for the EAF--LF--VD--CC process flow of a domestic steel plant． As a result of aluminates floating，lower T［O］con￾tent in the steel before the LF refining was shown，while nitrogen content in the steel gradually increased during the whole flow． Large size inclusions ( about 50 μm) ，namely，silicic manganates with low melting point，complexes with Na2 O and magnesium aluminate spinels with a little CaO，appeared at the LF--VD stage and disappeared completely after the tundish process． Small size inclusions ( ＜ 10 μm) could be found during the whole refining flow． Their size at different refining stages was similar to each other，while smal￾ler than that of the casting blank． The small size inclusions were complex oxides which consist of Mg，Al，Si，Ca and CaS respectively． The composition of the small size inclusions gradually moved to the liquid phase region during the smelting flow，and competition exis￾ted between CaO and MgO contents in these inclusions． Macro inclusions ( ＞ 100μm) in the casting blank included complex inclusions caused by entrapped slag，MgO--CaO inclusions from refractories and endogenous aluminate inclusions coated by a CaS layer，whose composition was similar to small size inclusions in the smelting processes． The macro aluminate inclusions were easily broken into chain and further resulted in cracks in the steel during the rolling process． Hence，it is suggested to prolong the steel standing time after the VD operation to remove detrimental aluminate inclusions． KEY WOＲDS drill pile; steelmaking; non-metallic inclusions; crystallization; evolution 收稿日期: 2013--12--17 基金项目: 国家自然科学基金资助项目( 51372019，51074009，50874013) ; 国家高技术研究发展计划资助项目( 2013AA032003) ． DOI: 10． 13374 /j． issn1001--053x． 2014． 11． 006; http: / /journals． ustb． edu． cn 石油钻杆是钻井时用于传递动力和输送泥浆的 主要工具，需承受各种复杂交变的载荷和腐蚀性工