Ni-Cr, Ni-W合金の高温強化因子について

抄録

In order to obtain a fundamental knowledge for the study of austenitic heat resisting steels and superalloys, the strengthening factors affecting high temperature creep of nickel-chromium and nickel-wolfram alloys are discussed using Sherby’s equation: \dotε_s=Aγ^3.5(σ⁄E)⁵D, where \dotε_s is the steady state creep rate, γ is the stacking fault energy, σ is the applied stress, E is Young’s modulus, D is a diffusion constant. First of all, the Sherby’s equation was ascertained for pure metals. It seems that the most important factor affecting the high temperature strength of nickel-chromium alloys is the decrease of stacking fault energy by the addition of chromium, and that of nickel-wolfram alloys is the decrease of stacking fault energy and of diffusion velocity by wolfram. The contributions of Young’s modulus and dislocation locking by solute were also estimated.