Plates having cooling channels, and method for welding the plates and increasing a dimension of the cooling channels adjacent the welded section

Abstract

A plate-like-object manufacturing method, plate-like objects, a gas-turbine combustor, and a gas turbine, in which degradation in the cooling performance can be suppressed, the time required for manufacturing a gas-turbine combustor can be shortened, and deterioration of the working environment can be prevented are provided. A plate-like-object manufacturing method includes a step of forming a plate-like object by stacking a plurality of plates and arranging a plurality of channels, through which a cooling medium flows, side-by-side between the plurality of plates; and a step of arranging a plurality of the plate-like objects side-by-side in a direction in which the channels are arranged, butting the plurality of plate-like objects against each other, and performing welding at an abutment section. The channels adjacent to the abutment section extend along the abutment section and have a greater dimension in the direction in which the channels are arranged, as compared with that of other channels.