Combustion system including a transition piece and method of forming using a cast superalloy

A method of forming a one-piece cast transition piece comprising:

• providing a transition piece pattern;
• dipping the transition piece pattern in a slimy material to build up the slurry material;
• firing the slurry material to produce a transition piece shell;
• introducing a molten material including molten metal to the transition piece shell;
• and
• solidifying the molten material to form the one-piece cast transition piece.

A combustion system comprising:

• a combustor;
• a transition piece comprising:
• a body defining a flowpath and enclosure, the body having a rounded inlet section for receiving combustion products from the combustor and an outlet end for flowing the combustor products into a first stage nozzle of a gas turbine;
• wherein the transition piece comprises a one-piece casting construction, the transition piece being formed from a nickel-based superalloy, and
• wherein the transition piece has a thick-to-thin transition ratio of wall thickness of thick transition to wall thickness of thin transition of about 1.1 to about 2.5.