硼对高铬铸铁铸渗层组织和性能的影响  

Effect of Boron on Microstructure and Properties of Casting Infiltration Layer of High Chromium Cast Iron

作　　者：张倩倩 陈冲 张聪 马晶博 张程 毛丰 ZHANG Qianqian;CHEN Chong;ZHANG Cong;MA Jingbo;ZHANG Cheng;MAO Feng(College of Material Science and Engineering,Henan University of Science and Technology,Luoyang 471003,Henan,China;National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology,Luoyang 471003,Henan,China;Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南科技大学金属材料磨损控制与成型技术国家地方联合工程研究中心,河南洛阳471003 [3]北京科技大学钢铁共性技术协同创新中心,北京100083

出　　处：《材料导报》2022年第4期178-184,共7页Materials Reports

基　　金：河南省重点研发与推广专项(科技攻关)项目(192102210166,192102210009)。

摘　　要：本工作利用自熔铸渗技术在ZG45钢表面复合不同硼含量的高铬铸铁铸渗层,研究了硼对高铬铸铁铸渗层组织和性能的影响。利用相图计算软件Thermo-Calc计算分析了不同硼含量下铸渗层的凝固过程,并采用SEM-EDS、XRD和显微硬度仪对不同成分铸渗层的微观组织和硬度进行分析。结果表明:铸渗层与ZG45钢基体达到冶金结合,在结合界面处未观察到微孔洞、微裂纹等缺陷,获得了厚度为10~12 mm的铸渗层。不含硼的铸渗层组织由α-Fe和α-Fe+M_(7)C_(3)共晶组织组成。加入微量的硼元素后,铸渗层组织主要由α-Fe与α-Fe+M_(7)C_(3)+M_(2)B共晶组织组成,与相图计算结果基本吻合。随着硼含量的增加,共晶组织逐渐细化,M_(7)C_(3)碳化物含量减少,M_(2)B型硼化物增多,铸渗层硬度逐渐增加。当硼含量为0.72%(质量分数)时,铸渗层硬度最高达到1190HV。对铸态试样进行淬火+低温回火热处理后,铸渗层共晶硼化物与碳化物发生聚集长大,同时在铸渗层基体中伴有二次相的析出,试样铸渗层的洛氏硬度均有提升。热处理试样冲击磨损实验表明,铸渗层磨损表面主要以切削犁沟、疲劳剥层和剥落坑为主,并有少量微小的凿坑。硼含量为0.72%(质量分数)时,试样的抗冲击磨损性能最佳。In the present work,the high chromium cast iron with different boron content was compounded on the surface of ZG45 steel by the self-melting casting infiltration technique.The effect of boron addition on the microstructure and properties of high-chromium cast iron casting infiltration layer was investigated.The phase diagram calculation software Thermo-Calc was used to calculate and analyze the solidification process of the casting infiltration layer with different boron content.SEM-EDS,XRD and microhardness tester were used to analyze the microstructure and hardness of the casting infiltration layer.The results show that the casting infiltration layer achieves metallurgical bonding with ZG45 steel matrix.No defeat such as microvoids and microcracks on the bonding interface was observed,and the casting infiltration layers with an average thickness of 10—12 mm were obtained.The casting infiltration layer without boron is composed ofα-Fe andα-Fe+M_(7)C_(3) eutectic structures.With a small amount of boron,the casting infiltration layers mainly consist ofα-Fe matrix andα-Fe+M_(7)C_(3)+M_(2)B eutectic structure,which is consistent with the calculation results of phase diagram.With the increase of boron content,eutectic structure is refined,the amount of M_(7)C_(3) carbide decreases,and the amount of M_(2)B boride increases.The microhardness of casting infiltration layer also increases.When the boron content is 0.72wt%,the microhardness of casting infiltration layer reaches 1190HV.After quenching and then tempering at low temperature,eutectic borides and carbides in the casting infiltration layer aggregate and grow,and secondary phases are precipitated in the matrix of the casting infiltration layer.Rockwell hardness of the casting infiltration layer is improved.The impact wear test of heat-treated samples shows that the wear surface of cast infiltration layer mainly consists of cutting furrows,fatigue delamination,spalling pits,and a few tiny gouges.When boron content is 0.72wt%,the impact wear resistance reache

关 键 词：铸渗 含硼高铬铸铁 相图计算 界面 冲击磨损 

分 类 号：TG14[一般工业技术—材料科学与工程]