摘要
在激光焊金刚石工具设计中,刀头的过渡层设计不仅需要保证其与基体具有较高的焊接强度,且需考虑与刀头工作层材料的相容性和工艺性。文章以Fe-Co基激光焊过渡层为研究对象,研究Mn对其激光焊接性能的影响。试验结果表明:随着Mn含量的增加,激光焊缝、过渡层的硬度会出现相反的变化趋势,激光焊缝的硬度渐升,而过渡层硬度渐降低,且随着Mn含量的提升,激光焊接强度则是先升后降。当Mn含量<1%时,焊缝断裂形式为脆性断裂,而当Mn含量在1%～1.5%时,焊缝断裂形式为韧性断裂,Mn含量为1.5%时,激光焊缝内残留气孔的数量最低,焊接强度最高;随着Mn含量的增加,激光焊缝的组织由珠光体+上贝氏体,逐渐转变为上贝氏体+马氏体,而且马氏体组织的含量显著增加;当Mn含量为1.5%时,马氏体组织晶粒比较细腻,而当Mn含量为2%时,马氏体组织晶粒比较粗大,使得焊接强度有所降低。
In the design of laser welded diamond tools,the backing of the segment should not only needs to ensure the high welding strength between the segment and substrate,but also consider the compatibility and workability with the working layer of the segment.In this paper,the influence of Mn on the laser welding performance of Fe-Co backing with laser welding was studied.The results shew that the hardness of laser welded seam changed in the opposite trend of the hardness of the backing with the increase of Mn content:the hardness of laser welded seam will increase gradually,while the hardness of the backing will decrease gradually.But during the increase of Mn content,the laser welded strength increased first and then decreased.When the Mn content dropped to be less than 1%,the fracture mode of weld was brittle fracture.But when the Mn content was between 1%and 1.5%,the fracture mode of weld was ductile fracture.When Mn content was 1.5%,the number of residual pores in laser weld was the lowest and the welding strength was the highest;during such increasing,the microstructure of laser weld was gradually changed from pearlite+upper bainite to upper bainite+martensite,and the content of martensite increased significantly.The martensite grain was more delicate when the Mn content was 1.5%.But when the Mn content was 2%,martensite grain was coarser,which made the welding strength to be decreased.
作者
张许红
王成军
胡伟立
李忠林
ZHANG Xu-hong;WANG Cheng-jun;HU Wei-li;LI Zhong-lin
出处
《超硬材料工程》
CAS
2018年第6期10-15,共6页
Superhard Material Engineering
关键词
激光焊接
过渡层
金刚石工具
锰元素
laser welding
transition layer
diamond tool
Manganese element
