Gas Turbine Blade and Manufacturing Method Thereof

A method for manufacturing a gas turbine blade in which a part of the blade base material composed of a γ′ phase precipitation strengthened type Ni-based superalloy, comprising the steps of:

• stripping said blade base material;
• applying a solution heat treatment in which the γ′ phase of said blade base material is dissolved again;
• welding to form the part composed of said weld metal by welding in an inert gas chamber using a TIG method which uses a welding wire composed of a Ni-base material containing Ta from 4.8 to 5.3 wt. %, Cr from 18 to 23 wt %, Co from 12 to 17 wt %, W from 14 to 18 wt. %, C from 0.03 to 0.1 wt. %, Mo from 1 to 2 wt. % and Al from 1 wt % or less, in which the oxygen content is 0 to 30 ppm, the Ti content 0 to 0.1 wt. %, and the Re content 0 to 0.5 wt. %;
• applying a HIP treatment in which a HIP treatment is performed at a temperature from 1100 to 1150° C. after said welding step;
• and
• applying an aging treatment in which an aging treatment is performed at a temperature from 835 to 855° C. after the step.