ZHU Tenghui, LIU Li, WANG Gaojian, et al. Development of cold-resistant solid wire and microstructure of high speed train bogies[J]. 2018,48(3):9-17.DOI:
To ensure the safe and reliable operation of high-speed trains,the welded joints of bogies must have the ability to serve in wide area,such as the extremely cold regions of Northeast China and Russia. Therefore,it is increasingly important to develop the welding material for bogie with cold resistant and high toughness. In this paper,a new type of 55 G Ⅱ solid wire with high cold resistant and toughness was developed by using microalloying design. The transition behavior of droplets was observed by using high speed phase system. The mechanical properties of weld metal were tested and the fracture morphology of the specimens were observed by scanning electron microscope(SEM). Besides,the corrosion resistance and fatigue limit of the weld metal were studied. The results showed that,the newly developed solid wire has excellent arc stability under 250 A and 150 A current conditions,such as short circuiting or breaking times and small spatter particles. The microstructure of the weld metal is mainly composed of bainite,pearlite and ferrite. The maximum impact energy at-40 ℃ is 129 J while the average one is 96 J at-60 ℃. The weight loss of 1 000 h alternate immersion corrosion is3.56% and the fatigue limit of the welded joint is 374 MPa through 1×107 cycles under the 4 stress level.
关键词
转向架焊丝疲劳性能力学性能断口形貌腐蚀失重比
Keywords
bogie welding wirefatigue performancemechanical propertyfracture morphologycorrosion weight loss ratio