%A"Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany)]" %A"Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany)]" %A"Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany)]" %A"Hensley, H [Siemens Power Generation (Germany)]" %D1998 %I; Technical Research Centre of Finland, Espoo (Finland) %2 %J[] %K20 FOSSIL-FUELED POWER PLANTS, 36 MATERIALS SCIENCE, COMBINED-CYCLE POWER PLANTS, GEARS, MECHANICAL SHAFTS, ULTRASONIC TESTING, CHROMIUM-NICKEL-MOLYBDENUM STEELS, STRESSES, QUALITY ASSURANCE, DAMAGE, HEAT TREATMENTS, STEAM TURBINES %PMedium: ED; Size: pp. 523-534 %TUltrasonic test of highly stressed gear shafts %XIn the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs. %0Conference %NVTT-SYMP-185(v.2); CONF-980999-;Other: ON: DE99730863; ISBN 951-38-4577-X; TRN: FI9903079 %1 %CFinland %Rhttps://doi.org/ Other: ON: DE99730863; ISBN 951-38-4577-X; TRN: FI9903079 FI %GEnglish