Effect of Mechanism of Phosphorus and Boron on Creep Deformation of Alloy 718

Abstract

The effect of P and B on creep deformation of alloy 7 1X was studied. It was found that both P and B increase the resistance to creep deformation with P being a much stronger strengthening element than B. This result is in sharp contrast with the general belief that P is a detrimental element. Also of note is the strong synergistic effect of P and B revealed in alloy 7 18. The combined addition of P and B generated an increase in stress rupture life time or a decrease in the creep rate much greater than the sum of the individual effect of P or B. The P and B combined effect peaked at approximately P = 0.022 wt.% and B = 0.012 wt.% and can be expressed as: