Z phase formation in martensitic 12CrMoVNb steel

Studies of minor phase evolution in a 12CrMoVNb martensitic steel, creep tested for durations of up to 100000 h at 550°C and 600°C, have revealed the presence of a hitherto unknown complex nitride precipitate having a tetragonal unit cell similar to that of Z phase, previously only reported in certain niobium bearing austenitic steels. This paper describes the electron diffraction and X-ray microanalysis studies leading to the discovery of this...