Deep Hole Drilling for Steam Turbine Rotors
Steam turbine rotors are large forgings that rotate at high speed inside the turbine casing. They need a through-bore running the full length for borescope inspection access and for balancing. In my experience, the bore is one of the most critical features of the rotor because it enables the periodic inservice inspections that prevent catastrophic failure. Rotor Specifications and Material Properties A typical steam turbine rotor might be 4-8 meters long with a 100-200mm bore. The material is a high-strength alloy steel like 3.5NiCrMoV. The rotor can weigh 20-50 tons, which makes handling a major consideration. ...