Effect of precipitation strengthening on high-temperature creep in Incoloy 800 type steel

Abstract

Structural changes in high-temperature creep and annealing within the temperature range 825–1175K are discussed with the aim of determining the effect of M₂₃C₆ and probably also γ-Ni₃(AI, Ti) precipitation strengthening in creep. Though no precipitation of γ' was detected under the present conditions, dislocation motion at lower temperatures, i.e. 825–975 K, was influenced by the short-range ordering of the alloy. The effect of M₂₃C₆ precipitation on dislocations at higher temperatures, 975–1175 K, represents a limiting value of the applied stress necessary for straining of the annealed specimens and contributes to the internal stress on creep.