The paper presents the susceptibility of AE44 magnesium alloy to electrochemical corrosion and stress corrosion cracking (SCC). The evaluation of the intensity of the interaction of the corrosive environment was carried out using the corrosion tests and the Slow Strain Rate Test (SSRT). Corrosion tests performed in 0.1 M Na2SO4 solution (immersion in solution and under cathodic polarization conditions) revealed that the layer of corrosion products was much thicker after immersion test. The results of SSRT showed that the AE44 alloy deformed in the solution was characterized by higher plasticity compared to the alloy deformed in the air after immersion in solution. Moreover, the fractures were characterized by different morphology. In the case of an alloy deformed in the solution under cathodic polarization many microcracks on the fracture were observed, which were not observed in the case of the alloy deformed in the air.

The paper presents the results of research on the impact of impurities in the feed ingots (master heat) on the precipitation of impurities in

the ATD thermal analysis probe castings. This impurities occur mostly inside shrinkage cavities and in interdendritic space. Additionally,

insufficient filtration of liquid alloy during pouring promotes the transfer of impurities into the casting. The technology of melting

superalloys in vacuum furnace prevents the removal of slag from the surface of molten metal. Because of that, the effective method of

quality assessment of feed ingots in order to evaluate the existence of impurities is needed. The effectiveness of ATD analysis in

evaluation of purity of feed ingots was researched. In addition the similarities of non-metallic inclusions in feed ingots and in castings

were observed.