Corrosion behaviour of thixoformed and heat-treated ZA27 alloys in NaCl solution
(1. Institute ″Gosa″, University of Belgrade, Milana Rakica 35, 11000 Belgrade, Serbia;
2. Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia;
3. ″Vin?a″ Institute of Nuclear Sciences, University of Belgrade, Mike Petrovi?a Alasa 12-14, 11001 Belgrade, Serbia)
2. Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia;
3. ″Vin?a″ Institute of Nuclear Sciences, University of Belgrade, Mike Petrovi?a Alasa 12-14, 11001 Belgrade, Serbia)
Abstract: The influence of corrosion on the microstructure of thixoformed and heat-treated ZA27 alloys was investigated. The microstructure of ZA27 alloy was affected by heat treatment. The process of electrochemical corrosion occurs in both ZA27 alloys through the area of η phase. According to the results of immersion test and electrochemical measurements, the corrosion rate of the thixoformed ZA27 alloy is at least 50% lower than that of the thixoformed and thermally processed alloy. This indicates the unfavourable influence of applied heat treatment (T4 regime) on the corrosion resistance of the thixoformed ZA27 alloy.
Key words: ZA27 alloy; thixoforming; corrosion; heat treatment; microstructure