Study on Hot Isostatic Pressing to Heal Liquation Cracks in HAZ of Nickel Base Superalloy Welds

Abstract

The weldability of Inconel 713C casted alloy and Inconel 718 forged alloy for high tmeperature components was investigated as a dissimilar metal joint by electron beam welding. As a result, fine Equation cracks in HAZ of the joint were detected by microscopic examination. This type of crack was very difficult to be prevented only by changing EB welding parameters. Then, it was experimentally found that hot isostatic pressing as a thermomechanical process could completely healed such fine cracks. And tensile strength at elevated temperature and creep rupture stress of HIPed joints after EB welding were not less than those of Inocnel 718 alloy.