摘要
对转向架SMA490BW耐候钢在不同焊接线能量下进行了单丝MAG焊接试验,研究了线能量对接头显微组织与力学性能的影响。结果表明：焊接线能量在10～32 kJ/cm时,随着线能量的增加,焊缝金属中的晶内针状铁素体逐渐转变为条状或块状的铁素体,晶界侧板条铁素体尺寸增大;热影响区晶粒逐渐粗化,粒状贝氏体和晶界的先共析铁素体增加,当线能量达到32 kJ/cm时晶界的先共析铁素体几乎呈网状分布。不同线能量下,焊接接头拉伸试样均断裂于母材。随着线能量的增加,焊缝金属和热影响区的冲击功逐渐减小,对于焊缝金属、热影响区,线能量分别不超过25、32 kJ/cm时,其冲击功满足在-40℃下不小于27 J的要求。
The single wire MAG welding tests of SMA490 BW weathering steel for bogie frame was carried out under different welding line energies, and the influence of welding line energy on microstructure and mechanical properties of the welded joints was investigated. The results show that when the welding line energy is in the range of 10 kJ/cm to 30 kJ/cm,with the increase of welding line energy, the intragranular acicular ferrite in weld metal is transfromed to strip or block ferrite and the size of side plate ferrite at the grain boundary increases; the grains in the heat affected zone gradually coarsen, the contents of granular bainite and preeutectoid ferrite at grain boundary increase, and when the linear energy reaches 32 kJ/cm,the proeutectoid ferrite at grain boundary is almost distributed in the network form. Under different linear energy, the tensile specimens of welded joints are all fractured in the base metal. The impact energy of both weld metal and heat affected zone decreases gradually with the increase of the line energy. For the weld metal and heat affected zone, when the welding line energy is not more than 25 kJ/cm and 30 kJ/cm respectively, the impact energy at-40 ℃ is not less than the requirement of 27 J.
作者
张合礼
杨蔚
王永波
金成
史春元
ZHANG Heli;YANG Wei;WANG Yongbo;JIN Cheng;SHI Chunyuan(CRRC Qingdao Sifang Locomotive and Rolling Stock Co.,Ltd.,Qingdao 266111,China;Dalian Jiaotong University,Dalian 116028,China)
出处
《热加工工艺》
CSCD
北大核心
2018年第17期215-218,共4页
Hot Working Technology
