In this project we propose a research on a new process with the aim of its industrialization. This is a new hyper-deformation process that is applicable to metallic tubes. During this process, the microstructure of the material is fragmented by an extreme plastic deformation (torsion) and develops an ultra-fine microstructure that approaches nano-structure. This transformation attributes to the material exceptional mechanical properties. Namely, the elastic limit of the material can be multiplied by approaching the maximum theoretical limit. During this process, the tube is twisted by severe plastic deformation under a high hydrostatic pressure. The dimensions of the tube do not change during the test. The material is sheared around the axis of the tube. This process was invented recently by the partners of the present project and published in the journal Scripta Materialia [Severe plastic deformation of metals by high pressure tube twisting "by L.S. Tóth, M. Arzaghi, J.J. Fundenberger, B. Beausir, O. Bouaziz, R. Arruffat-Massion, Scripta Materialia, Volume 60, Issue 3 (2009), pp 175-177] and was received very favourably by the scientific community of the field. The process was called 'HPTT' (High Pressure Tube Twisting). The first tests were conducted on aluminium and copper. In collaboration with our industrial partner - ARCELOR MITTAL - we propose in this extensive research project a detailed study on the feasibility of the process on steel tubes for industrial HPTT process. While it is well known in the literature that hyper-deformation is an effective method to obtain nano-structured materials, a massive industrialization of the various processes proposed in this area still remains to be done (see State of the art section in document B). Our ambition is to develop an equipment suitable for HPTT hyper-deformation of low alloyed IF steel tubes. Microstructural studies will be carried out to control the microstructure. Various mechanical tests will be needed to test the properties obtained on the hyper-deformed materials. In addition, simulations will help the understanding and control of the various process parameters.