| 摘要 |
A gas turbine nozzle segment (10) has outer and inner bands (12, 14) and a vane (16) extending therebetween. Each band has a side wall (40), a cover (20) and an impingement plate (22) between the cover and nozzle wall defining two cavities (24, 26) on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through apertures (30) of the impingement plate to cool the nozzle wall. The side wall of the band has an intumed flange (40) defining with the nozzle wall (18) an undercut region (44). The outer surface of the side wall is provided with a step (60) prior to welding the cover to the side wall. A thermal barrier coating (64) is applied in the step and, after the cover is welded to the side wall, the side wall is finally machined to a controlled thickness removing all, some or none of the coating. <IMAGE> |
