Author/Authors :
Mobarake، نويسنده , , M. Iranpour and Nili-Ahmadabadi، نويسنده , , M. and Poorganji، نويسنده , , B. and Fatehi، نويسنده , , A. and Shirazi، نويسنده , , H. and Furuhara، نويسنده , , T. and Parsa، نويسنده , , Habibi and Nedjad، نويسنده , , S. Hossein، نويسنده ,
Abstract :
Effect of large-strain deformation by equal channel angular pressing on the microstructure of a martensitic age hardenable steel, namely 18 Ni (3 0 0) maraging steel, was studied by means of transmission electron microscopy. Equal channel angular pressing was carried out on the solution-annealed steel up to four passes at room temperature through the route Bc using a die with an inner angle of 90°. It was found that the initial martensitic structure of the solution-annealed steel evolves to a heterogeneously deformed structure consisting of ultrafine grains and lamellar dislocation cell blocks. Selected-area electron diffraction patterns revealed large orientation spread within the deformed structure. High density of dislocations and elastic lattice distortions were found in the deformed and aged microstructures.
Keywords :
ultrafine grain , Equal channel angular pressing , maraging steel , martensite
