Dislocation substructure and precipitation in type 316 stainless steel deformed in creep

The dislocation substructure and precipitation in type 316 stainless steel deformed in creep have been investigated using a transmission electron microscope. Creep tests were carried out at 823, 873 and 923 K over a broad range of stress levels. The rupture lives varied in the range of 100 to 139000 h. The dislocation substructure was found to depend on the test temperature and stress level. Uniformly distributed dislocations, dislocation cells, equiaxed subgrains and elongated subgrains have been observed depending on test conditions. M23C6 carbides were present in the matrix at almost all the test conditions. The substructural observations are correlated with the mechanisms of creep deformation. (author)