TURBINE CASING AND METHOD OF MANUFACTURING THE SAME

PROBLEM TO BE SOLVED: To provide a method of manufacturing a turbine casing for reducing the time required for welding, reducing degree of thermal distortion of a half-ringlike member, and achieving stable work environment to improve work efficiency when manufacturing a turbine casing. SOLUTION: In this method of manufacturing the turbine casing, the half-ringlike member composed of a plurality of tapered half-ringlike members 16, 20, 24, 32, semicylindrical ringlike members 28, 34, and half-disclike reinforcing ribs 18, 22, 26, 30 is divided into blocks A-C, and the half-ringlike members are overlapped in parallel on a surface plate F per block. Then, a horizontally facing welding line (w) formed between the half-ringlike members is welded to form the blocks A-C integrally. Next, the blocks A-C are arranged in order in the longitudinal direction of base members 12a, 12b, and the blocks and the blocks A-C and the base members 12a, 12b are temporarily welded. The welding line (w) of the temporarily welded semicylindrical casing 10 is inverted to become substantially parallel with a surface of the surface plate F, the welding line (w) is made to face sideways, and then real welding is performed. COPYRIGHT: (C)2011,JPO&INPIT