元素B对自蔓延焊条焊接工艺及接头显微组织影响  

Effect of B content on welding process and microstructure of manual SHS welding

作　　者：杨辉[1] 张国栋[1] 张建强[1] 张富巨[1] 

机构地区：[1]武汉大学水力机械过渡过程教育部重点实验室,430072

出　　处：《焊接》2015年第11期22-26,69-70,共5页Welding & Joining

基　　金：国家自然科学基金资助项目(51374154);湖北省自然科学基金资助项目(2014CFB707)

摘　　要：研究了元素B的不同添加量对铜基自蔓延焊条焊接工艺性和焊接接头显微组织的影响。试验结果显示,元素B的适量加入可以降低自蔓延焊条燃烧速率、抑制反应喷溅,并具有改善焊缝金属组织和细化晶粒的作用。在最佳添加量0.5%B时,焊缝脱渣良好,液态金属铺展均匀,焊缝气孔率显著降低;焊缝金属无明显宏观偏析,且晶粒细小均匀。当B加入量高于1.0%时,焊条工艺性能急剧恶化,焊缝金属发生严重宏观偏析,形成明显的富Fe区和富Cu区,元素B与合金元素化合形成硬质相,弥散分布于富Fe区,过剩B偏析于晶界,增加了焊缝金属的裂纹敏感性。The influence of the additive amount of B in welding rod on the welding process and microstructure of manual SHS welded joint was studied.The results show that the appropriate content of B can slow down the combustion velocity of welding rod,inhibit splash phenomenon,refine the grain and improve the microstructure of weld seam.In the range of 0 ~ 2.0%,the optimal mass fraction of B proves to be 0.5%.At this proportion,the favorable welding quality can be obtained,which includes the better deslagging effect,more homogeneous spreadability and fewer porosities in weld.The macrosegregation about Fe,Cu in the weld seam is little.Meantime,fine and uniform grain can be obtained.However,when the mass fraction of B is more than 1.0%,the welding quality deteriorates noticeably.At the same time,serious macrosegregation is observed.Cu-rich region and Fe-rich region come into being in weld seam,B and other alloying elements combine to form hard phase,which distributes in Fe- rich region.Crack sensitivity of weld seam will also increase as a result of the phenomenon that excess B tends to segregate at grain boundaries.

关 键 词：手工自蔓延焊 接焊接工艺性 显微组织 性能 

分 类 号：TG456.9[金属学及工艺—焊接]