Próby statycznego i dynamicznego skręcania w zastosowaniu do oceny zdolności do odkształceń twardych stali

The paper describes the results of investigations of the influence of the strain-rate and the heat treatment conditions on the ductil properties of two sorts of tool steels. The measure of the steel ductile properties was the angle of plastic strain during the torsion tests. It was found that with growing of the strain-rate the ductile properties of the steel SW7M decrease and the ductile properties of the steel SW18 increase. The impact tests have been carried out on the two specially designed stands the operation principles of which are explained in the figures 1 and 3. The stand shown in the figure 1 is designed on the basis of the Charpy hammer. It permits to achieve the maximum strain-rate up to 6.6 rad/s (fig. 2). The experiments carried out on the stand shown in the figure 3, where a torsion bar was a source of energy, the
maximum strain-rates of the range 80-115 rad/s were achieved.