| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a machining method free from generation of flaws caused by the laser beam on a wall surface of a straight hole when a diagonal hole is machined. SOLUTION: When a shaped cooling hole is formed in a profile part of a stationary blade of a gas turbine, the focal point is first moved, and a surface of the profile part is irradiated with the laser beam in the diagonal direction to form a diagonal hole 2b. Then, the surface is irradiated with the laser beam at right angles, and a straight hole is machined to form a straight hole 2a. Because generation of flaws by the laser beam in a wall surface of the straight hole 2a as often experienced in the conventional method can be prevented, a sound shaped cooling hole can be efficiently formed, and the stationary blade of the gas turbine capable of withstanding the high temperature of 1500 deg.C can be manufactured with excellent efficiency.</p> |
