Effects of Shrinkage Cavities on Creep Property of Radial Forging GH4169 Alloy at Different Positions

The shrinkage cavity size and amount of the radial forging GH4169 alloy had been investigated,and then the creep properties of the alloy at different positions were tested at 650 ℃ and 725 MPa.The results show that the shrinkage cavities were main at grain boundaries,both the amount and volume of the surface shrinkage cavities were larger than those of the center place.The creep life of the surface metal was the shortest which was about half as long as that of the center place.The fracture modes of the creep samples cut from different locations were all ductile dimples.The shrinkage cavities occured at grain boundaries were one of the important crack origins during the alloy creep.