Improvement of mechanical properties of Inconel 718 electron beam welds-influence of welding techniques and postweld heat treatment

Effects of electron beam oscillation techniques (sinusoidal, square, triangular, ramp, circle, and elliptical) in controlling Nb segregation, Laves formation, and tensile behavior of Inconel 718 electron beam welds were studied. Effects of various postweld heat treatments on tensile behavior were compared. Elliptical beam oscillation technique resulted in less Nb segregation and discontinuous finer Laves in the interdendritic regions compared to that of unoscillated beam weld. Response to aging was better for welds made with elliptical oscillated beam compared with welds made with unoscillated beam. Oscillated beam welds exhibited better mechanical properties than unoscillated beam welds in both solution-treated and aged and directly aged conditions. © 2008 Springer-Verlag London Limited.