Long-term strength of steam-turbine rotors in the stress concentration zone

The results from calculating the long-term strength of single-piece forged rotors using the natural mechanistic procedure [1] are compared with the experimental long-term strength characteristics of the models of high-temperature disk rims [2, 3] and with the field data on failures of such rims [4]. A new experimentally substantiated calculation procedure is proposed. The use of the procedure for estimating the long-term strength of the rotors of turbines now in service shows that the failure probability of the rotor rims of 800 MW turbines that have been in service for 100 000 h is approximately equal to 30%. © Nauka/Interperiodica 2006.