Method for closing used hole on top of gas turbine blade

Abstract

A tip plug 56 is capped on a boss section 55a so as to fit to a hole 55 which is used for detaching a core which is formed in a blade tip section 52 of the gas turbine blade. A butt-section T is melted so as to form a butt-welding section 57 by using a YAG laser beamthere; thus, the hole 55 is plugged by the tip plug 56. Also, parameters such as an interval between the butt-section T, a member for forming the tip plug 56, condition for a laser welding operation, and a defocus position of the laser beam are optimized. By doing this, it is possible to control the entering heat amount and prevent the solidification cracking and the liquation cracking reliably. Furthermore, it is possible to melt and weld the butt-welding section more strongly by using a laser having a narrow bead width; thus, it is possible to improve the manufacturing process efficiently and produce a product in uniform quality repeatedly.

Description

technical field [0001] The invention relates to a method for plugging a hole in a gas turbine blade tip for extracting a core formed inside the blade. The invention relates to a method for plugging a hole in a gas turbine blade tip, wherein the method enables reliable plugging of the hole and the plugging works very efficiently. Background technique [0002] Gas turbine blades are exposed to high temperature operating gases. Therefore, nickel-based superalloys containing relatively large amounts of Al and Ti are generally used to form gas turbine blades in order to improve their creep resistance under high temperature conditions. In addition, to cope with extremely high temperature conditions, it is more common to employ directional solidification and single crystal components in order to adjust the direction of crystal growth in the single crystal components. [0003] On the other hand, a method of making coolant flow in gas turbine blades (hereinafter referred to as turb...

AI Technical Summary

Problems solved by technology

[0007] However, when the tip plug 56 is welded to the hole 55 formed at the tip portion 52 in a TIG welding operation, there is a problem that it is difficult to pre-work the edge for the welding operation because the pre-work of the edge Complicated; welding operation requires job skills and practical experience; and welding operation costs tend to increase

Also, it is not possible to control the plug and bottom plate part ( image 3 The spacing between 55a) in , therefore, there is a problem of changing the melting depth, and more seriously, cracks may occur in the welded part

Images