低频磁场对轧辊埋弧堆焊组织及性能的影响  

Effect of Low-frequency Magnetic Field on the Microstructure and Mechanical Property of Submerged-arc Deposited Metal on Roll

作　　者：常云龙[1] 梅强[1] 张伟 夏云才 谢天男[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870 [2]大连重工.起重集团有限公司硬面技术研究所,辽宁大连116052

出　　处：《中国表面工程》2011年第6期98-103,共6页China Surface Engineering

基　　金：沈阳市人才专项(2008030103055);辽宁省教育厅重点实验室项目(2009S072)

摘　　要：为提高堆焊层熔敷金属的力学性能,在轧辊埋弧堆焊过程中外加低频脉冲纵向磁场,通过对堆焊层硬度和显微组织的分析,研究了磁场参数对轧辊埋弧堆焊层金属组织及力学性能的影响规律。通过对不同磁场参数下堆焊表层试样的硬度及其组织的分析,发现低频脉冲纵向磁场的电磁搅拌作用能够影响晶粒的形核与长大过程,细化晶粒,提高堆焊层硬度,探讨了低频纵向磁场改善堆焊层金属的组织形态、细化晶粒和提高硬度的机理。结果表明:当磁场参数为Ip=300A,Ib=200A,f=5Hz时,焊缝组织细化最为明显,晶粒尺寸减小到30.1μm,硬度比不加磁场时提高了4.5HRC。外加低频纵向磁场通过电弧的旋转来搅拌熔池,改变晶粒的结晶过程,使焊缝晶粒得到细化,提高堆焊层硬度。In order to improve the mechanical properties of the overlaying welding layer deposited metal, the additional low-frequency impulsion longitudinal magnetic field was applied during the submerged are overlaying welding on roll. The effect of low-frequency magnetic on metal microstructure and mechanical property of the deposited metal on roll was studied through analysing overlaying welding layer hardness and mierostrueture. The electro-magnetic stirring effect of the low-frequency impulsion longitudinal magnetic field can affect the crystal nucleation and growth process. The crystal grain is refined. The overlaying welding layer hardness is improved. Through analysing the different of parameters, hardness and microstructure of overlaying welding layer samples, the mechanism how the metal microstructure shape and hardness are improved and the crystal grain is refined by additional low-frequency longitudinal magnetic field has been discussed. The results indicated that microstructure of weld is refined clearly, crystal grain size is reduced to 30.1 t^m, and compared to without magnetic field hardness increased 4.5 HRC when peak magnetic field current is 300 A, back- ground magnetic field current is 200 A and magnetic field frequency is 5 Hz. Molten pool is stirring by the additional low -frequency longitudinal magnetic field, the solidification process is charged, the crystal grain is refined and overlaying welding layer is improved.

关 键 词：纵向磁场 堆焊 晶粒细化 

分 类 号：TG455[金属学及工艺—焊接]