The appearance of magnesium and its effect on the mechanical properties of Inconel 718 with low sulfur content

The appearance of magnesium and its effect on the mechanical properties of Inconel 718 with low sulfur content were investigated. The results show that magnesium has almost no effect on the tensile properties of Inconel 718 at room temperature, 500°C and 650°C. When the content of sulfur is lower than 10 ppm, magnesium can decrease the stress rupture life of Inconel 718 at 650°C, 686 MPa. The fractography and microstructure analysis by means of scanning electron microscopy (SEM) reveal that magnesium has little effect on the rupture method and microstructure of Inconel 718, i.e. grain size and δ-phase, etc. The Auger research shows that there is no segregation of magnesium at grain boundaries. The main appearance method of magnesium is Mg(O,S).