自保护药芯焊丝熔敷金属中O、N的控制及其对显微组织和韧性的影响  

Control of O,N and Their Impact on Microstructure and Toughness of Deposited Metal of Self-Shielded Flux Cored Wire

作　　者：张占伟[1] 李午申[1] 薛振奎[2] 白世武[2] 

机构地区：[1]天津大学材料科学与工程学院,天津300072 [2]中国石油天然气管道科学研究院,廊坊065001

出　　处：《天津大学学报》2010年第2期186-189,共4页Journal of Tianjin University(Science and Technology)

基　　金：国家高技术研究发展计划(863计划)资助项目(2006AA03Z505)

摘　　要：采用氧氮分析仪、光学显微镜、电子显微镜及电子能谱仪研究了自保护药芯焊丝熔敷金属中O、N含量对夹杂物类型、显微组织及低温冲击韧性的影响规律.结果表明,对于BaF2-Al-Mg渣系自保护药芯焊丝,药芯中不低于4%的LiF,可有效改善电弧稳定性;同时在电弧区生成Li3N,降低熔覆金属中的N含量.通过向药芯中加入10%的Fe2O3和5%的MnO2,可将熔敷金属中Al质量分数降低至0.84%,而氧质量分数提高到85×10-6,得到以Al2O3为主的圆形夹杂,增加晶内异质形核核心,焊缝组织得到细化.通过对O、N含量的有效控制可显著提高熔敷金属的低温韧性.The impact of O,N content in deposited metal of self-shielded flux cored wire on the type of inclusions,microstructure and low-temperature impact toughness has been studied with oxygen-nitrogen analyzer,optical microscopy,electron microscopy and electron spectroscopy.The experimental results reveal that in self-shielded flux cored wire of BaF2Al-Mg slag system,LiF addition of no less than 4% of the total flux core can improve arc stability effectively and generate Li3N in the arc zone so that nitrogen content in deposited metal can be reduced to 210×10-6.Addition of 10% Fe2O3 and 5% MnO2 in flux can reduce the residual Al content in deposited metal to 0.84% and raise the oxygen content to 85×10-6.The inclusion of Al2O3 instead of AlN is the main inclusion type and weld microstructure is refined.It is thus concluded that effective control of O and N content can enhance the low-temperature toughness of the weld significantly.

关 键 词：自保护药芯焊丝 O N 夹杂物 韧性 

分 类 号：TG422.3[金属学及工艺—焊接]