DISLOCATION SUBSTRUCTURE AND PRECIPITATION IN TYPE-316 STAINLESS-STEEL DEFORMED IN CREEP

The dislocation substructure and precipitation in type 316 stainless s teel deformed in creep have been investigated using a transmission ele ctron microscope. Creep tests were carried out at 823, 873 and 923 R o ver a broad range of stress levels. The rupture lives varied in the ra nge of 100 to 139000 h. The dislocation substructure was found to depe nd on the test temperature and stress level. Uniformly distributed dis locations, dislocation cells, equiaxed subgrains and elongated subgrai ns have been observed depending on test conditions. M(23)C(6) carbides were present in the matrix at almost all the test conditions. The sub structural observations are correlated with the mechanisms of creep de formation.