摘要
通过焊接热模拟试验研究了管线钢的焊接热循环过程,结合扫描电镜、背散射电子衍射系统、透射电镜和硬度试验表征和分析了热影响区软化区的组织变化、晶体学特征和第二相析出行为。结果表明,对于母材组织为多边形铁素体和针状铁素体的深海管线钢,焊接热影响区的软化区出现在峰值温度为1000~900℃的细晶区。采用V微合金化和低的焊接热输入量可以使组织有效晶粒尺寸减小、小角度晶界比例和位错密度增加,从而有效地改善热影响区细晶区的软化问题。
In this paper,the welding thermal cycle process of deep-sea pipeline steel was investigated using welding thermal simulation.The microstructure variation,crystallography characteristic and second-phase precipitation behaviors of the softening zone of heat affected zone(HAZ)were characterized and analyzed by combining with the scanning electron microscope,electron back-scattered diffraction,transmission electron microscopy and hardness testing.The results show that HAZ softening zone appears in the fine-grained zone with a peak temperature of 1000~900℃for deep-sea pipeline steel whose base metal microstructure is the polygonal ferrite and acicular ferrite.Using V microalloying and low welding heat input can reduce the grain size,increase the proportion of small-angle grain boundaries and the dislocation density effectively.Thus,the softening problem of the HAZ fine-grained region can be effectively improved.
作者
余腾义
周磊磊
李拔
杨萍
Yu Tengyi;Zhou Leilei;Li Ba;Yang Ping(Pangang Group Research Institute Co.,Ltd.,Panzhihua 617000,Sichuan,China;Engineering Steel Research Institute,Central Iron and Steel Research Institute,Beijing 100081,China;School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243002,Anhui,China)
出处
《钢铁钒钛》
CAS
北大核心
2020年第5期159-165,共7页
Iron Steel Vanadium Titanium
关键词
深海管线钢
HAZ软化区
焊接热模拟
热输入
位错密度
小角度晶界
depp-sea pipeline steel
HAZ softening zone
weld thermal simulation
heat input
dislocation density
low angle grain boundary
