Analysis of solidification and liquation cracks formation of Zhs6u superalloy electron beam welding at different heat inputs.

In this research, susceptibility of the formation of liquation and solidification cracks during the electron beam welding of the Zhs6u superalloy was investigated. The aim of this research is obtaining of the desirable parameters of the electron beam welding for the repair process and investigation of the effect of different values of heat input on properties and microstructure of HAZ and weld area. After the pre-weld heat treatment cycle, all test samples were welded by different values of current and welding speed and by the constant value of voltage. Microstructural investigations revealed the detrimental effect of the increase in the heat input on the susceptibility of the formation of the solidification cracks in the weld region of the samples. The microstructure of the weld region was consisted of the matrix phase including and phase, eutectic phase and the carbide phase with Chinese scripts morphology. Chemical composition of these phases was similar to the chemical composition of the equivalent phases in the base material, but the morphology of the phases was completely different.