Research On The Chemical Corrosion For Detecting Temper Embrittlement Of Steam Turbine Rotor

The solution of picric acid and sodium dodecyl benzene sulfonate (SDBS) is used to corrode the aged turbine rotor steel samples,it supplies a better corroding conditions to determine the embrittlement degree of material using the methord of forming film.The best experiment conditions were determined by using the orthogonal test together with the observation to the microstructures of the aged turbine rotor steel specimen: saturated picric acid, 0.005 mol/L sodium dodecyl benzene sulfonate, pH 2.0, 35min and 25℃.It is discovered that the significance of the effect of this 5 factors on the wide of grain boundary is picric acid concentration, pH value, SDBS concentration, temperature, time. The chemical corrosion experiments were carried out on the turbine rotor steel specimen with different fracture appearance transition temperature at various temperatures. The dependency of FATT₅₀ on the chemical corrosion parameters,chemistry component of the meterial,mechanical capability parameters,grain size as well as temperature is analysed by measuring and analysing the microstructure of samples by the software of Photoshop;used the SPSS to do multiple linear regression analysis, and the models for predicting the FATT50 with pridiction errors of±20℃was constructed. It is possible to forecast the age of turbine rotor using the chemical corrosion.