Abstract
Equal-Channel Angular Pressing (ECAP), High Pressure Torsion (HPT) and Accumulative Roll Bonding (ARB) are typical processing procedures of severe plastic deformation. They can reduce the grain size to well within the submicrometer range. This paper reviews principles and characteristic features of the three major processes and summarizes recent studies reported on pure Fe and steels. Microstructural features and related mechanical properties are introduced for each process. Important aspects in conducting each process are described, and practical applicability and future development are discussed in terms of scaling-up and continuous operation.