焊缝中M-A组元对X70管线钢焊缝组织及冲击性能的影响  

Influence of M-A constituent on microstructure and impact property of weld metal of X70 pipeline steel

作　　者：薛屺[1] 刘德臣[1] 尹长华[2] 范玉然[2] 

机构地区：[1]西南石油大学材料科学与工程学院,四川成都610500 [2]中国石油天然气管道科学研究院,河北廊坊065000

出　　处：《金属热处理》2013年第8期32-37,共6页Heat Treatment of Metals

基　　金：西安市科技计划项目(CX1250)

摘　　要：针对X70管线钢在自保护药芯焊丝焊接下焊接接头冲击值的离散性进行研究。试验通过对其焊后不同填充层次进行显微组织观察,结合焊后M-A组元的定量分析,探讨了焊接热循环作用对X70管线钢焊缝组织的影响。结果表明,多层焊接焊缝组织中粗晶区保留了部分原有的晶体学位向关系,晶内M-A组元明显减少。受多次焊接热循环作用,焊缝组织表现出来的冲击值极低,主要是焊接时峰值温度使部分焊缝组织奥氏体化,多取向的针状铁素体在填充层粗晶区晶内形核,M-A含量增加,块状M-A在晶内及晶间出现,这种焊缝组织表现出了极差的冲击性能。Discrete impact property of welded joint of X70 pipeline steel was discussed under self shielded flux cored wire（FCAW-S）.Microstructure of the different filling welded layer was observed and the M-A constituent content was quantitatively analyzed,and the influence of welding heat cycle on X70 pipeline steel was discussed.The result shows that the microstructure of CGHAZ produced by multilayer welding retains part of the original crystallographic orientation relationship,and intracrystalline M-A constituent reduces significantly.Affected by many welding heat cycle,the weld structure possesses extremely low impact value.It is due to the nucleation of multi-orientation acicular ferrite in coarse grain area of the filling layer and the increase of massive intracrystalline and intercrystalline M-A constituent.

关 键 词：X70管线钢 M-A组元 针状铁素体 冲击性能 

分 类 号：TG407[金属学及工艺—焊接] TG115.6