Electrochemistry Study For Hot Embrittle Of 30Cr2MoV Turbine Rotor Steel

The electrochemical behaviors of the aged turbine rotor steel in picric acid solution was investigated by the potentiostatic pulse technique. The polarization conditions for evaluating the aging of turbine rotor steel in picric acid solution were optimized by using the orthogonal test together with the observation to the microstructures of the specimen. The polarization conditions determined are pH 2.3, 0.004 mol/L sodium dodecylbnzene sulfonate, 0.04 mol/L picric acid, +0.35v passivation voltage, -0.25v activation voltage, t₁=t₂=5s pulse time, 4 min stabilization, 2 min passivation. The potentiostatic pulse test polarization experiments were carried out on the turbine rotor steel specimen with different fracture appearance transition temperature at various temperatures. And the reactivation current density is selected to characterize the polarization behavior of aged turbine rotor steel in picric acid solution. The dependency of FATT₅₀ on the electrochemistry parameters,chemistry component of the meterial,mechanical capability parameters,grain size as well as temperature is analysed by multiple linear regression analysis, and the models for predicting the FATT₅₀ with pridiction errors of -15℃were constructed.