工程科学学报，第38卷，第12期：1720-1727,2016年12月 Chinese Journal of Engineering,Vol.38,No.12:1720-1727,December 2016 D0l:10.13374/j.issn2095-9389.2016.12.009:http://journals.ustb.edu.cn 电渣重熔过程冷却强度对含镁H13钢中碳化物的 影响 贺宝，李晶，史成斌，王吴 北京科技大学钢铁治金新技术国家重点实验室，北京100083 ☒通信作者，E-mail:ling@usth.cdu.cm 摘要研究电渣重熔过程冷却强度对含镁H13钢凝固组织和碳化物偏析的影响.采用光学显微镜、扫描电镜、透射电镜、X 射线衍射仪等分析凝固组织及碳化物的特征.研究发现，钢锭的凝固组织均为马氏体组织、残余奥氏体及一次碳化物.H13 钢电渣锭中主要析出的一次碳化物为V,C,、MC、MxC,及M。C.随着冷却强度增加，电渣锭边部碳化物的尺寸减小且分布更 加均匀，但是碳化物的类型不发生变化.电渣重熔过程中冷却强度增加促进钢中镁对夹杂物的变性能力，经过镁变性后生成 的Mg0·AL,O,为TiN的析出提供形核质点，MgO·AL,O,和TN的复合夹杂物能够促进一次碳化物异质形核，从而细化一次碳 化物。 关键词模具钢：电渣重熔：冷却：微观组织：碳化物 分类号TF744 Effect of cooling intensity on carbides in Mg-containing H13 steel during the electroslag remelting process HE Bao,LI Jing,SHI Cheng-bin,WANG Hao State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:lijing@ustb.edu.cn ABSTRACT The effect of cooling intensity on the carbide segregation and solidification microstructure of an H13 as-east ingot with Mg addition was studied during the electroslag remelting process.The solidification microstructure and the carbide characteristics of the steel were analyzed by optical microscopy,scanning electron microscopy,transmission electron microscopy,and X-ray diffraction anal- ysis.The results show that the solidification microstructure of the ingot consists of martensite,retained austenite and primary carbides. Carbides in the electroslag remelting ingot are VsC,,MC,MaC and M.C.With the increasing of cooling intensity,the size of carbides in the edge of the electroslag remelting ingot decreases,the distribution of these carbides becomes more homogeneous,but the types of carbides remain unchanged.Increasing the cooling intensity improves the modification of inclusions by Mg.The formed Mgo. Al,O,arising from Mg treatment provides preferred nucleation sites for TiN.These complex inclusions promote the heterogeneous nucleation of primary carbides,consequently refining primary carbides. KEY WORDS die steel:electroslag remelting:cooling:microstructure:carbides H13钢是一种国内外广泛应用的空冷硬化型热作： 状偏析严重，特别是粗大碳化物，导致国产H13钢的 模具钢，具有良好的淬透性、热强性、韧性等四.国产 使用寿命与国外的相差几倍之多四 H13模具钢通常存在粗大的一次共晶碳化物，而且带 电渣重熔通过提高钢的洁净度、降低枝晶偏析和 收稿日期：2016-02-29 基金项目：国家自然科学基金资助项目(51374022)工程科学学报，第 38 卷，第 12 期: 1720--1727，2016 年 12 月 Chinese Journal of Engineering，Vol． 38，No． 12: 1720--1727，December 2016 DOI: 10． 13374 /j． issn2095--9389． 2016． 12． 009; http: / /journals． ustb． edu． cn 电渣重熔过程冷却强度对含镁 H13 钢 中 碳 化 物 的 影响 贺 宝，李 晶，史成斌，王 昊 北京科技大学钢铁冶金新技术国家重点实验室，北京 100083  通信作者，E-mail: lijing@ ustb． edu． cn 摘 要 研究电渣重熔过程冷却强度对含镁 H13 钢凝固组织和碳化物偏析的影响． 采用光学显微镜、扫描电镜、透射电镜、X 射线衍射仪等分析凝固组织及碳化物的特征． 研究发现，钢锭的凝固组织均为马氏体组织、残余奥氏体及一次碳化物． H13 钢电渣锭中主要析出的一次碳化物为 V8C7、MC、M23C6及 M6C． 随着冷却强度增加，电渣锭边部碳化物的尺寸减小且分布更 加均匀，但是碳化物的类型不发生变化． 电渣重熔过程中冷却强度增加促进钢中镁对夹杂物的变性能力，经过镁变性后生成 的 MgO·Al2O3为 TiN 的析出提供形核质点，MgO·Al2O3和 TiN 的复合夹杂物能够促进一次碳化物异质形核，从而细化一次碳 化物． 关键词 模具钢; 电渣重熔; 冷却; 微观组织; 碳化物 分类号 TF744 收稿日期: 2016--02--29 基金项目: 国家自然科学基金资助项目( 51374022) Effect of cooling intensity on carbides in Mg-containing H13 steel during the electroslag remelting process HE Bao，LI Jing ，SHI Cheng-bin，WANG Hao State Key Laboratory of Advanced Metallurgy，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: lijing@ ustb． edu． cn ABSTＲACT The effect of cooling intensity on the carbide segregation and solidification microstructure of an H13 as-cast ingot with Mg addition was studied during the electroslag remelting process． The solidification microstructure and the carbide characteristics of the steel were analyzed by optical microscopy，scanning electron microscopy，transmission electron microscopy，and X-ray diffraction anal￾ysis． The results show that the solidification microstructure of the ingot consists of martensite，retained austenite and primary carbides． Carbides in the electroslag remelting ingot are V8 C7，MC，M23 C6 and M6 C． With the increasing of cooling intensity，the size of carbides in the edge of the electroslag remelting ingot decreases，the distribution of these carbides becomes more homogeneous，but the types of carbides remain unchanged． Increasing the cooling intensity improves the modification of inclusions by Mg． The formed MgO· Al2O3 arising from Mg treatment provides preferred nucleation sites for TiN． These complex inclusions promote the heterogeneous nucleation of primary carbides，consequently refining primary carbides． KEY WOＲDS die steel; electroslag remelting; cooling; microstructure; carbides H13 钢是一种国内外广泛应用的空冷硬化型热作 模具钢，具有良好的淬透性、热强性、韧性等［1］． 国产 H13 模具钢通常存在粗大的一次共晶碳化物，而且带 状偏析严重，特别是粗大碳化物，导致国产 H13 钢的 使用寿命与国外的相差几倍之多［2］． 电渣重熔通过提高钢的洁净度、降低枝晶偏析和