摘要
用电子显微镜观察了超级钢的熔化极混合气体保护脉冲焊三种焊接参数下的焊接接头粗晶区的精细结构,并测量了显微硬度沿焊缝的分布。结果表明:三种焊接参数下的热影响区中均未出现软化现象;随着热输入线能量的升高,粗晶区中的铁素体形态和碳化物的形态、分布和取向也变得复杂多样。在线能量低的接头粗晶区中,铁素体以块状为主,碳化物数量较少,呈粒状;在线能量较高的接头粗晶区中,铁素体以板条状为主,并在其上分布大量等轴状的亚单元,碳化物分布在亚单元的边界上或亚单元内部;在线能量高的接头粗晶区中,铁素体为板条状、块状,碳化物呈粒状,棒状等平行地分布在铁素体上,并与板条长轴呈不同的夹角。
The welded joints of an ultrafine grained steel were made by PC-MAG welding process under three welding parameters. The microhardness along the welding seam were measured. The fine structures of the coarse grained zone was studied by TEM. The results show that there are no softened zone in the heat affect zone, and the morphologies of ferrite and carbide, distribution and direction of carbides become more complexity with increasing the heat input. When the heat input is low the morphology of ferrite is block-like the amount of carbides is less, which have graing-like shape and distribute along single direction in ferrite. When the heat input is middling, there are many equaxied subunits in ferrite laths, and carbides are distributed inside the subunits and at their boundaries. When the heat input is high, the ferrites are lath-like or block-like, the carbides are grain-like, rod(needle)-like etc., and distribute along different directions in the ferrite.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第5期505-509,共5页
Acta Metallurgica Sinica
基金
国家重点基础研究发展规划资助项目 G1998061500
关键词
超细晶粒钢
粗晶区
精细结构
亚单元
ultra fine grained steel
coarse grained zone
fine structure
subunit
