Prověření možnosti náhrady etalonové třídy hřídelové oceli alternativními ocelemi

Abstract

The bachelor's thesis dealt with the examination of the mandatory quality parameters of three standardized classes of steel intended for the production of the shaft component. The aim of the bachelor's thesis was to find out whether ETG 88 steel can be replaced by 42CrMoS4 type steels in the drawn and peeled state, by means of a comparative analysis of complex material properties. The steels were supposed to have better or at least the same properties as the ETG88 steel., The chemical composition, microstructure incl. micropurities of steel; then static tensile tests, impact tests in bending and checking the fatigue limit. The fatigue limit was evaluated on test specimens fitted with an initiation notch with a geometry and dimension simulating the notch effect of the transition of the shaft diameter from 18mm to 9mm. In addition to the analyzes carried out, it would be advisable to focus on machinability and carry out machinability tests. Machinability is essential from the point of view of production costs in the serial production of shafts. It was found that ETG 88 steel contains several times more sulfur and will be better in terms of machinability. The mechanical properties are better for both types of 42CrMoS4 steel. The comparison was difficult. In practice, steel 42CrMoS4 is normally used in the quenched a tempered state, so it would be appropriate to focus on this variant in the future.