Schwingungsverschleißfestigkeit von plasmanitriertem, 34 CrAlMo 5

Abstract

Fretting Fatigue Strength of Plasmanitrided 34 CrAlMo 5Fretting fatigue load here means oscillating sliding movements of very small amplitude (1-3 pm) and synchronous fatigue load. Characteristic of this is the appearance of frettings. These surface damages lead to the formation of microcracks, which spread and finally lead to the premature fatigue failure of the component. To simulate such processes of damage, which are known of the bearing surfaces of roller bearing races, of turbine blades and of shaft-hub-combinations, a fretting bridge apparatus is used. The plasmanitriding and plasmanitrocarburizing of metals are thermochemical heat treatments, which change the microstructure of near to surface areas. By means of this the mechanical and technological properties of components, e.g. wear and corrosive resistance as well as fatigue strength, are improved. Due to the advantages of the process, plasmanitriding is already used in many regions of production. Investigating the fretting fatigue strength of plasmanitrided respectively plasmanitrocarburized 34 CrAlMo 5 shows, that these treatments improve the fatigue strength values to a level 14% higher, the fretting fatigue strength increases about 50%.