工程科学学报，第37卷，第3期：329-335,2015年3月 Chinese Journal of Engineering,Vol.37,No.3:329-335,March 2015 DOI:10.13374/j.issn2095-9389.2015.03.011:http://journals.ustb.edu.cn 喷射成形含铌M3型高速钢的组织和耐磨性 王和斌”，侯陇刚”，卢林”，张金祥”，崔华》，黄进峰)四，张济山” 1)北京科技大学新金属材料国家重点实验室，北京1000832)北京科技大学材料科学与工程学院，北京100083 ☒通信作者，E-mail:huangi@263.net 摘要采用喷射成形技术制备了M3型高速钢和以Nb替代V的M3型高速钢.利用扫描电镜、X射线衍射、差示扫描量热 仪和金相显微镜研究了Nb对M3型高速钢组织的影响.喷射成形能有效消除宏观偏析，细化组织.以Nb代V,提高了MC型 碳化物开始析出温度，大量MC相先于共晶反应析出，呈独立的近球形分布于晶界，同时其尺寸减小.由于消耗大量C,抑制 了共晶反应，M,C片层数量减少且厚度变薄，其在热变形过程中更易于分解，进一步增加了组织均匀性.低温低载荷时含铌 的M3型高速钢抗磨损性能显著优于M3高速钢，温度升高到500℃时磨损机制逐渐以氧化磨损为主，两合金的抗磨损性能差 距减小，主要原因是大量呈弥散球形分布的含铌MC型碳化物能有效提高高速钢的磨粒磨损抗性，而其对抗氧化性能并无明 显作用 关键词高速钢：喷射成形：铌：显微组织：磨损抗性 分类号TG142.45 Microstructure and wear resistance of spray-formed M3 high speed steel with niobium addition WANG He--bin”,HOU Long-gang'',LU Lin',ZHANG Jin-xiang,CUI Hua》,HUANG Jin-feng》,ZHANG Ji--ham》 1)State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China 2)School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:huang-i-@263.net ABSTRACT M3 high speed steel (HSS)with or without niobium addition was prepared by spray forming,and the effect of niobium on the microstructure of M3 HSS was investigated by scanning electron microscopy (SEM)combined with energy dispersive X-ray (EDX)spectroscopy,X-ray diffraction (XRD)analysis,differential scanning calorimetry (DSC)and optical microscopy (OM).Fi- ner and uniformly-distributed grains without macrosegregation appear in the as-deposited HSS,and the addition of niobium tends to shift the precipitation of primary MC-type carbides to a higher temperature.Plenty of refined niobium-containing MC carbides precipi- tate as isolated sphere particles in the grain boundaries before onset of eutectic reaction.Niobium mainly appears in primary MC-type carbides by consuming carbon,which suppresses the degree of eutectic reaction to a large extent,leading to the decrease in both amount and size of M,C lamella carbides.The refined metastable M,C carbides in Nb-containing HSS can be completely decomposed easily during hot deformation,and the homogeneity of carbides in Nb-eontaining HSS is improved.The wear-resistant property of Nb- containing HSS is superior to that of M3 HSS at a lower load or temperature.But this gap is reduced with temperature rise.The main reason is that the large number of refined primary MC carbides can improve the abrasive wear resistance of HSS,but have no effect on its oxidation resistance. KEY WORDS high speed steel:spray forming:niobium:microstructure;wear resistance 收稿日期：2014-08-01 基金项目：国家重点基础研究发展计划资助项目(2011CB606303)工程科学学报，第 37 卷，第 3 期: 329--335，2015 年 3 月 Chinese Journal of Engineering，Vol． 37，No． 3: 329--335，March 2015 DOI: 10． 13374 /j． issn2095--9389． 2015． 03． 011; http: / /journals． ustb． edu． cn 喷射成形含铌 M3 型高速钢的组织和耐磨性 王和斌1) ，侯陇刚1) ，卢 林1) ，张金祥1) ，崔 华2) ，黄进峰1) ，张济山1) 1) 北京科技大学新金属材料国家重点实验室，北京 100083 2) 北京科技大学材料科学与工程学院，北京 100083  通信作者，E-mail: huang-j-f@ 263． net 摘 要 采用喷射成形技术制备了 M3 型高速钢和以 Nb 替代 V 的 M3 型高速钢． 利用扫描电镜、X 射线衍射、差示扫描量热 仪和金相显微镜研究了 Nb 对 M3 型高速钢组织的影响． 喷射成形能有效消除宏观偏析，细化组织． 以 Nb 代 V，提高了 MC 型 碳化物开始析出温度，大量 MC 相先于共晶反应析出，呈独立的近球形分布于晶界，同时其尺寸减小． 由于消耗大量 C，抑制 了共晶反应，M2C 片层数量减少且厚度变薄，其在热变形过程中更易于分解，进一步增加了组织均匀性． 低温低载荷时含铌 的 M3 型高速钢抗磨损性能显著优于 M3 高速钢，温度升高到 500 ℃时磨损机制逐渐以氧化磨损为主，两合金的抗磨损性能差 距减小，主要原因是大量呈弥散球形分布的含铌 MC 型碳化物能有效提高高速钢的磨粒磨损抗性，而其对抗氧化性能并无明 显作用． 关键词 高速钢; 喷射成形; 铌; 显微组织; 磨损抗性 分类号 TG142. 45 收稿日期: 2014--08--01 基金项目: 国家重点基础研究发展计划资助项目( 2011CB606303) Microstructure and wear resistance of spray-formed M3 high speed steel with niobium addition WANG He-bin1) ，HOU Long-gang1) ，LU Lin1) ，ZHANG Jin-xiang1) ，CUI Hua2) ，HUANG Jin-feng1)  ，ZHANG Ji-shan1) 1) State Key Laboratory for Advanced Metals and Materials，University of Science and Technology Beijing，Beijing 100083，China 2) School of Materials Science and Engineering，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: huang-j-f@ 263． net ABSTＲACT M3 high speed steel ( HSS) with or without niobium addition was prepared by spray forming，and the effect of niobium on the microstructure of M3 HSS was investigated by scanning electron microscopy ( SEM) combined with energy dispersive X-ray ( EDX) spectroscopy，X-ray diffraction ( XＲD) analysis，differential scanning calorimetry ( DSC) and optical microscopy ( OM) ． Fi￾ner and uniformly-distributed grains without macrosegregation appear in the as-deposited HSS，and the addition of niobium tends to shift the precipitation of primary MC-type carbides to a higher temperature． Plenty of refined niobium-containing MC carbides precipi￾tate as isolated sphere particles in the grain boundaries before onset of eutectic reaction． Niobium mainly appears in primary MC-type carbides by consuming carbon，which suppresses the degree of eutectic reaction to a large extent，leading to the decrease in both amount and size of M2C lamella carbides． The refined metastable M2C carbides in Nb-containing HSS can be completely decomposed easily during hot deformation，and the homogeneity of carbides in Nb-containing HSS is improved． The wear-resistant property of Nb￾containing HSS is superior to that of M3 HSS at a lower load or temperature． But this gap is reduced with temperature rise． The main reason is that the large number of refined primary MC carbides can improve the abrasive wear resistance of HSS，but have no effect on its oxidation resistance． KEY WOＲDS high speed steel; spray forming; niobium; microstructure; wear resistance