Effects of Section Size on the Stress Rupture Lives of the Machined Thin-Walled Slab Specimen of DD6 Single Crystal Superalloy at 980 °C/250 MPa

Abstract

The effects of section size on the stress rupture lives of DD6 single crystal superalloy at 980 °C/250 MPa were investigated adopting machined thin-walled slab specimen. Stress rupture fractograph was analyzed. The results show that stress rupture lives of machined thin-walled slab specimen decline slightly with the reduction of section size at 980 °C/250 MPa, and stress rupture lives of thin-walled specimen are slightly lower compared with that of 5 mm in diameter standard cylindrically specimen, however, the stress rupture lives of thin-walled specimen are still about 200 hours. The decrease in effective loading area caused by oxidation is the main factor for the reduction of thin-walled stress rupture lives.