REPETITIVE CORRUGATION STRAGHTENING AND ROLLING ASA STATEOF THE ART BULKDEFORMATION PROCEDURE

Severe plastic deformation (SPD) is a promising procedure to achieve ultrafine grained (UFG) microstructuresin metallic materials. The homogeneity of microstructure, large applied strains, minimum dimensional changesand industrial applicability are the significant issues that should be taken into consideration in SPD methods. The mostly applied SPD methods despite their widespread use, don t provide all the mentioned issues simultaneously. A new SPD process called repetitive corrugation and straightening rolling (RCSR), has been developed for fabrication of UFC metallic materials to induce high strains after repetitive cycles. RCSR consists of corrugated rolls accompanying the capability of changing the position of the samples duringdifferent routes. Samples of Fe-Ni-Mn martensitic steel sheets were intensively deformed to a large accumulated strain by RCSR procedure. The calculated applied strain after fifty cycles of processing was almost 10. Microstructural studies were done by the aid of optical and scanning electron microscopy. Theresults indicate that a more homogenous microstructure with minor dimensional changes and proper potential industrial application can be achieved.

Keywords:

Repetitive corrugation and straightening rolling , ultrafine grain , steel sheet