Flow passage forming plate, flow passage forming member assembly and vane including the same, gas turbine, manufacturing method of flow passage forming plate, and modification method of flow passage forming plate

A manufacturing method of a flow passage forming plate that defines a part of a gas flow passage through which combustion gas flows in a gas turbine, the manufacturing method comprising:

• an intermediate product forming step of forming an intermediate product of the flow passage forming plate by casting;
• and
• a part removing step of removing a part of the intermediate product, wherein
• the intermediate product created in the intermediate product forming step has:
• a plate main body having a gas path surface that faces a side of the gas flow passage, and an inner surface that faces the opposite side from the gas path surface;
• a peripheral wall that is provided along a peripheral edge of the plate main body, and protrudes, relative to the inner surface, toward an opposite-flow-passage side that is a side of the inner surface based on the gas path surface;
• and
• a ledge that protrudes along an inner wall surface of the peripheral wall, from the inner surface toward the opposite-flow-passage side, and receives an impingement plate having a plurality of through-holes, and
• in the part removing step, a part of the ledge in a wall extension direction in which the peripheral wall extends is removed.

A modification method of a flow passage forming plate that defines a part of a gas flow passage through which combustion gas flows in a gas turbine,

• the flow passage forming plate to be modified having:
• a plate main body having a gas path surface that faces a side of the gas flow passage, and an inner surface that faces the opposite side from the gas path surface;
• a peripheral wall that is provided along a peripheral edge of the plate main body, and protrudes, relative to the inner surface, toward an opposite-flow-passage side that is a side of the inner surface based on the gas path surface;
• and
• a ledge that protrudes along an inner wall surface of the peripheral wall, from the inner surface toward the opposite-flow-passage side, and receives an impingement plate having a plurality of through-holes,
• the modification method comprising a part removing step of removing a part of the ledge in a wall extension direction in which the peripheral wall extends.