Effects of Phosphorus on tensile and stress rupture properties of GH4169 alloy

Abstract

The influence of P on tensile properties at room temperature and 650℃ as well as the effects of P on rupture properties at 650℃/690 MPa of GH4169 alloy with standard heat treatment (STD) and direct aging heat treatment (DA) were investigated in this paper. Mechanism of the influence of P was also undertaken with microstructure and fractograph analysis. The results show that P content has little effect on tensile properties of alloys. While the stress rupture life improves significantly with an increase of P content due to grain boundary segregation of P increasing grain boundary bonding force. And P has less influence on stress rupture life of GH4169 alloy as STD than that as DA, which may be relevant to the enrichment of P on δ phase interface. Increasing P content from 0.006% to 0.019%, the stress rupture failure mode shows mainly transgranular fracture, decreased fraction of fine microvoids and deep dimple structure arises gradually.