Texture and mechanical properties of EUROFER 97 steel processed by ECAP

The EUROFER 97 steel was processed by equal channel angular pressing (ECAP) at 550 degrees C for four passes via route C. The starting material consisted of ferrite-martensite dual phase composed by small subgrains of about 0.5 mu m and low angle boundaries less than 5 degrees. The volume fraction of second phase particles was around 10 vol.%, besides a texture formed by several fibers orientations belonging to the zone axes < 110 >, < 111 > and < 112 >. Increasing ECAP deformation, this microstructure became into equiaxed grain structures of less than 1 mu m, and the misorientation between contiguous grains increased. This refinement of the microstructure was accompanied by the development of a new texture described by a family of fiber orientations related by rotations around axes < 110 > and < 111 >. Tensile tests have revealed that an ECAP treatment at 550 degrees C for two passes could significantly strengthen the tempered material still maintaining good ductility. (C) 2011 Elsevier B.V. All rights reserved.