Influence of a rolling process on the shape memory behavior in Fe-Mn-Si alloys

A. DRUKER; S. HEREÑÚ; A. BARUJ; J. MALARRÍA

Bochum, Alemania

Congreso; European Symposium on Martensitic Transformations ESOMAT 2006; 2006

Ruhr. Univ. Bochum

Many Fe-Mn-Si sheets, cold and hot rolled at different temperatures with different annealing conditions, were tensile-deformed to study critical martensitic transformation stress ¥ò¥ã¡æ¥å and the degree of recovery obtained during retransformation. It was observed that cold rolling produces a high density of dislocations enlarging the ¥ò¥ã¡ê¥å to almost 700 MPa, while the hot rolled sample, with a minor density of reticular defects, presents a ¥ò¥ã¡ê¥å =  491 MPa. On the other hand, cold and hot rolled samples annealed during 1 h. to 1000¨¬C, seem to have so few defects that the ¥ã¡ê¥å transformation occurs at stresses lower than 300 MPa. Coherently, DSR is 35%, 55% and 38% in cold rolled, hot rolled and annealed samples respectively. Amount and array of microstructural defects, left in the matrix after deformation and annealing processes, play a fundamental role on the characteristic parameters of the different samples.