In order to well evaluate the availability of electrochemical method using to detect the creep damage of martensitic heat resistant steel

a set of T92 internal pressure creep test samples with different creep damage degrees were selected. The microstructure evolution in the process of creep

especially the Laves phase precipitation behavior

was systematically characterized and analyzed; meanwhile

electrochemical response of Laves phase in alkaline were also investigated in detail. According to the scanning electron microscopy(SEM)

transmission electron microscopy(TEM) and electron probe X-ray micro-analyzer(EPMA) results

the Laves phase in T92 precipitated and grew rapidly during the internal pressure creep process. Its particle size and area percentage gradually increased

clustered and with element segregated and redistributed. According to potentiodynamic polarization curve in NaOH solution

Laves phase can selectively dissolve in strong alkali solution. When the concentration of NaOH reaches 8 mol/L

the current peak and corresponding electric value of selective dissolution of Laves phase are well correlated with the internal pressure creep time. In conclusion

the potentiodynamic polarization curve of T92 in strongly alkaline solution can effectively reflect the content of Laves phase

varying in consistent with its electric quantity; and can further associate with creep life damage. It is promising to be used as a nondestructive testing technology for the creep life assessment of pipelines in the field.