热输入对电力结构用Q460钢焊缝金属组织及冲击性能的影响  

Effect of heat input on microstructure and impact property of weld metal of Q460 steel for electric power structure

作　　者：肖红军[1] 田志凌[1] 崔冰[1,2] 宋威[1] 

机构地区：[1]钢铁研究总院先进钢铁流程及材料国家重点实验室,北京100081 [2]安徽工业大学材料科学与工程学院,安徽马鞍山243000

出　　处：《金属热处理》2017年第6期60-64,共5页Heat Treatment of Metals

摘　　要：采用熔化极气体保护焊对电力结构用Q460钢进行不同热输入的对接焊试验。利用金相显微镜、透射电镜和电子背散射衍射技术研究热输入对焊缝组织及冲击性能的影响。结果表明:3种热输入焊缝金属组织均为先共析铁素体、侧板条铁素体和针状铁素体及M-A组元。随着热输入的增加,焊缝组织中板条粗化,而先共析铁素体和侧板条铁素体增多,针状铁素体减少,M-A组元尺寸增大;焊缝金属中大角度晶界含量逐渐减少分别为0.54、0.40和0.37。尺寸较大的M-A组元及大角度晶界密度的降低是导致焊缝金属冲击吸收能量逐渐降低的主要原因。Butt welding test of Q460 steel for power structure with different heat input was carried out by gas metal arc welding. Effect of heat input on microstructure and impact property of weld metal was studied by means of optical microscopy,transmission electron microscopy and electron backscatter diffraction（ XRD）. The results show that microstructure of weld metal mainly consists of proeutectoid ferrite,ferrite side plate,acicular ferrite and M-A constituents under three kinds of heat input. With the increasing of heat input,the lath coarsen,but the proeutectoid ferrite and ferrite side plate increase,acicular ferrite decrease,and the size of M-A increase. The density of high angle boundaries in them decrease gradually,and reach 0. 54,0. 40 and 0. 37,respectively. The larger size of the M-A component and the decrease of the high angle grain boundary density are the main reasons for the decrease of the impact absorbed energy of the weld metal.

关 键 词：Q460钢 热输入 焊缝金属 组织 冲击性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]