Effect of temperature on stress corrosion cracking behaviour of P92 heat resistant steel in high temperature water

The effect of temperature on pitting initiation and stress corrosion cracking (SCC) of domestic P92 steel in high temperature water was investigated using linear sweep voltammetry and slow strain rate tests (SSRT). The results of linear sweep voltammetry show that P92 steel has weaker corrosion resistance with the increase of temperature. Pits along the grain boundary are easier to initiate at higher temperature water. The results of SSRT exhibit that P92 steel has the tendency of dynamic strain aging (DSA) and the SCC sensitivity in this test and these trends are more obvious with the increase of temperature. Scanning electron microscopy (SEM) observation results show that SCCs initiate from the grain boundaries and propagate intergranularly into the matrix in higher temperature water, moreover the characteristic of brittle fracture is also observed at the edge of fracture. ©, 2015, Editorial Office of Transactions of Materials and Heat Treatment. All right reserved.