| 摘要 |
PURPOSE:To improve reliability and resistance to abrasion by hardening with boron a tripping finger and the surface of a tripping piston in an emergency tripping device of a steam turbine. CONSTITUTION:An emergency tripping device has a tripping finger latch 1 and a tripping piston latch 2. In these parts, the surface is hardened using boron by forming a boron solid solution diffusion layer, in the same way as in forming a boron compound layer, by diffusing and penetrating boron on the metal surface at 900-1,000 deg.C for 3-20hr. This hardening treatment increases resistance to abrasion and improves reliability. |
