Korrosionsschwingfestigkeit der Stahlgußsorten G-X 5 CrNi 13 4 und G-X 5 CrNi 17 4 für Laufräder von Wasserkraftmaschinen und Pumpen

In this project the influence of different corrosive media on the fatigue behaviour of stainless cast steel alloys with 13 and 17% chromium content for hydraulic machines was investigated in the high cycle range. Hereby the possible range of media was covered by using tap water with 28 ppm chlorides, 10 mMol NaCl, as well as 1% NaCl and in the case of the higher alloyed steel additionally artificial sea water without and with cathodic protection. Further the influence of high mean stresses due to rotation of runners was also analysed. The results obtained on the lost of fatigue strength in dependence of corrosive media, mean stress and cycles to failure enable an aimed material's selection as well as an appropriate design and increase the reliability and security of water power machines.