Experimental investigating the effect of heat input on the strength of dissimilar welded joints of IN 713LC and AISI 4140 by electron beam welding method

Turbine engines mainly have non-homogeneous welded joints with various fusion-welding methods. In this research, the input energy was investigated as the main parameter with different in the voltage and beam current with welding speed of 6mm/s and focal radius of 1mm of the electron beam welding process. The connection quality of the samples after welding was determined with three characteristics of tension test and welding geometry along with examination of the fracture surface. It was observed that with the increase of input energy, the depth of penetration and the tensile strength of the connection increased. In this tensile test, three samples showed a tensile load of more than 80% of the base metal. It was also shown that failure in all the samples occurred from the interface area of 4140 steel with the fusion zone. With the increase of input energy, the heat affected zone increases. Comparing two samples with the same voltage and different beam current, and two samples with the same beam current and different voltage, shown that the influence of the beam current on the joint strength is significantly higher than the effects of beam voltage. Fractography shown that for the beam energy higher than 230 J / mm, the weld flexibility decreases. It can be explained by the high temperature and fast cooling rate in fusion zone for this sample. It was also shown that the acceptable tensile strength and suitable depth of penetration obtained in V40I40 sample with the beam energy of 267 J / mm.