Patent ID: 7568609

Claim:
A welding method for forming a molten build-up portion on a base material that is any one of a single crystal material and a unidirectionally solidified crystal material, comprising; forming a plurality of build-up portions on the base material while maintaining a predetermined gap between adjacent build-up portions; and forming a build-up portion in each of the predetermined gaps, wherein the predetermined gap is determined such that the build-up portion formed in each of the predetermined gap has a cross sectional area, in a direction perpendicular to a surface of the base material, substantially the same as a cross sectional area, in the direction perpendicular to the surface of the base material, of the plurality of build-up portions formed on the base material, wherein a symmetric thermal condition is kept during forming of the build-up portion so that a build-up layer is formed of at least one of the single crystal material and the unidirectionally solidified crystal material having the same crystal structure and orientation as the base material.