Microstructures And Mechanical Property Research On Materials And Welding Joint Of Bogie Frame

Welded frame bogie has the characteristics of light weight, high production efficiency, low cost, good structure of anti-fatigue performance and speed running, is the main form of the railway passenger car bogie frame. With the increase of train speed, the welded bogie frame under dynamic load is significantly enhanced, requirements of welded bogie frame must have enough strength and fatigue performance. In addition, the uncoordinated problems of corrosion resistance between bogie frame and car body have become increasingly prominent, seriously affected the service life and safe and reliable operation of railway passenger cars in our country. Therefore, selection of resistant structure materials in good corrosion resistance and welding material has very important realistic significance.The main contents of this paper are:using ER50-6, G383G3Sil,G424G3Sil welding wire weld Q345R, S355J2G3, S355J2W+N. The tensile, bending, impact, hardness and conventional mechanical properties and fatigue performance has been tested on the three kind of welded joint mechanical, the welding joint microstructure and fracture surface was observed and analysed, at the same time the three kinds of base metal, weld metal, welded joint were periodic infiltration corrosion test, corrosion products were observed and analyzed.The results show that:three groups of welded joints have high tensile strength and good bending performance and impact properties. The microstructure in weld metal contains proeutectoid ferrite along the grain boundaries of the columnar, pearlites and tenuous acicular ferrites appeared mainly within the gains. While weld metal of Q345R and S355J2G3aslo have little bainite. In weld metal of primarily for proeutectoid ferrite, acicular ferrite, pearlite and a small amount of granular bainite. Microstructure in the heat-affected zone mainly contains pro-eutectoid ferrite, acicular ferrite, a little pearlite and bainite, a quantity of Widmanstatten structures; the base metal contains ferrite and pearlite.While using ER50-6, G383G3Sil, G424G3Si1welding wire weld Q345R, S355J2G3, S355J2W+N, the fatigue limit of T-corner joints under conditions specified lifetime of1×107cycles were:133.5MPa,188.3MPa,154.5MPa.Among the the three steel base material the average weight loss rate of S355J2W+N is minimum, Q345R centered, S355J2G3is the highest; between the wire deposited metal the average weight loss rate of G424G3Si1is slightly higher than that of G383G3Si1; average weight loss rate of welded joints ER50-6and Q345R,G383G3Si1and S355J2G3, G424G3Si1and S355J2W+N are as follows:3.122g/(cm2-h)、2.7814g/(cm2·h)、2.6722g/(cm2-h).