Spoluautoři MENDROK Radek, KAWULOK Petr, UNUCKA Petr, KAWULOK Rostislav, OPĚLA Petr, RUSZ Stanislav, TUROŇ Rostislav, TUROŇOVÁ Petra, BOŘUTA Aleš

Phase composition of the studied high-alloy martensitic steel has been studied by metallographic methods, plastometric tests and thermodynamic calculations performed in the Thermo-Calc Software. Basic parameters of the formability and deformation resistance were determined depending on the forming temperature (800 – 1250 °C) and strain rate (0.1 – 17 1/s). Continuous tests to fracture were performed at two individual plastometers which enable performance of the uniaxial tension (Gleeble 3800) and/or torsion (SETARAM). The results were processed into the illustrative 3D maps that also reflect the effect of the phase composition at various deformation conditions. Since both plastometers work with different forming conditions and diverse state of stresses in the deformed sample, the mutual comparison of thus obtained results is interesting from the methodology viewpoint. The mean forming temperature increased by tens of °C during some torsion tests due to deformation heating and this value had to be corrected. The results of tension and torsion tests are quite compatible and display the positive influence of higher temperature and strain rate on formability of the given steel. The obtained data on the strength properties can be used for fast prediction of the power-force parameters of the operational forming technologies.