On the role of recovery in creep of precipitation-strengthened polycrystalline nickel-base alloys

An attempt is made to shed some new light on the role of recovery in creep of precipitation-strengthened polycrystalline nickel-base creep-resistant alloys, comparing some basic creep data for a Ni–16Cr–10W–4Mo–Ti–Al alloy with similar data for a low carbon 18Cr–12Ni stainless steel and a 15M2B–Fe–18Cr–12Ni in situ composite. The comparison suggests that the minimum creep strain rate of precipitation-stregthened polycrystalline nickel-base creep-resistant alloys is controlled rather by recovery (driven by internal stress affected by the presence of γ′-particles), than by dislocation glide/climb (driven by effective stress) past these particles. An urgent need to study in detail recovery in creep of precipitation-strengthened polycrystalline nickel-base alloys is emphasized.