Abstract
	The new methodology of determination of hot formability of metallic materials was developed, based on application of the wedge rolling test in laboratory conditions. The wedge rolling is suitable for quick evaluation of rollability and in co-operation with the following metallographic analyses for study of selected structure-forming processes as well. By means of this test data on the deformation limit of the structure may be obtained. In both cases the results depend, except for thermodynamic conditions, on stress state and therefore they often have only a qualitative character in relation to real technological processes. However, similarity of the laboratory and operational rolling creates conditions also for a quantitative comparison and application of the results in practice. As steels are in hot state mostly so plastic that not even single height reductions above 70 % during the wedge rolling test lead to cracks, it is advisable to carry out in manufacturing of initial samples additional modifications enabling easier development of cracks. This modification consists in milling out the defined notches on a side wall of the sample. The experiment was made with new types of high-alloyed steels. A special computer program KLIN was developed for determination of geometric dimensions of the rolled stock and calculation of its deformation characteristics, on the basis of the computer raster image analysis – scanned plan of the final rolled material. After taking samples from the rolled material a metallographic analysis of microstructures by means of optical microscopy was carried out.