Some aspects of Cr–Mo–V rotor steel damage due to long-term service from acoustic emission data

It is shown that damages accumulating in a rotor steel after more than 20 years in service under creep conditions at high temperatures reveal themselves in the change of acoustic emission (AE) parameters as compared with the initial structural state. The formation of clusters of AE activity is observed in zones 10$^2$–10$^4$ $\mu$m in size inducing a similar process by the shear mechanism in a neighbor zone with a larger effective elastic modulus. Hence, AE revealing of clusters of plastic deformation takes place.