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A mathematical model is proposed to calculate deformation resistance of C–Mn–Nb–V base high strength low alloy (HSLA) steels in finish rolling for temperatures from 700 to 900°C. The new method is based solely on the torsion test results that have been evaluated assuming a non-uniform strain over the sectional area of the specimen and falling strain rate throughout the continuous twisting at a constant rate. However, for commercial applications (involving large cumulative strains) the effective residual strain has been taken into account, as well as an original system of describing stress–strain curves and/or softening kinetics. On the basis of the last mentioned assumptions, the computation program has been written in BASIC language. It is concluded that such a model enables the roll force in plate rolling under conditions of retained static restoration to be predicted precisely.MST/590

On VSB -Technical University of Ostrava developed a method that uses the principle of severe plastic deformation to refine the structure and enhance mechanical properties of sheet metal strips. The greatest importance in practice represents an increase in yield strength and ultimate strength of sheet metal strips. The DRECE method (Dual Rolls Equal Channel Extrusion) is a newly developed method. Severe plastic deformation results in a high degree of the material deformation. The method can be used to produce metallic materials with a very fine grain structure. The paper analyses the effects of the values of angles of the newly developed forming tools on the achievement of mechanical properties in selected carbon steels by SPD process. The one type of steels (Ck55) was verified experimentally. Experiments were performed on the sheet metal strip with dimensions 58 (width) x 2 (thickness) x 1000 (length) mm with different inclination angle a.