In general, gas turbine combustors, turbine blades and vanes, called hot section parts, are considered consumables that require repair or replacement at periodic overhaul/inspections. The number of blades and vanes used for each power plant is ranges from several tens up to several hundreds. In order to assure timely supply for the demand by existing and/or new plants, it is extremely important to establish a manufacturing system for mass production. Additionally, there are continuing design changes resulting from both feed-back from actual operating units and new product development. Although these design changes generally add higher performance and added value to customer, the promotion of shortening the manufacturing lead time is a key of vital importance. To address this issue, MHI Takasago introduced one piece flow production lines into the row 1 blade and vane production section. This innovative change resulted in reduced distance between operations in the shops, reduction of stagnant items and improvement in the overall quality of the final product. Furthermore, the implementation of quality confirmation (in-process inspection) for the machined parts prevents defective parts from moving further in the manufacturing process and the continuous defection. As a result, a significant reduction in the defect rate has been accomplished. This trial has achieved an average reduction of total lead time of 20% for blades and 25% for vanes, compared with conventional lot production. Recently further improvements in production efficiency have been realized by improvement of tool and machining conditions, the equalization of machining time for each operation and eliminating unnecessary operations in standard works.

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