Effect of Long-Term Exposures at Elevated Temperature on Evolution of 08Kh18N10Т Steel Structure

Abstract—The effect of exposures in the range of 500–10 000 h at heating temperatures of 450–750°C on changes in the structure and properties of steel 08Kh18N10T has been studied. It has been found that, in the early stages of thermal aging at 450–550°C, the precipitates of finely dispersed carbides are formed, coherent with the austenitic matrix. With an increase in the holding time and aging temperature to 650°C, the sizes of Me₂₃C₆ carbide particles sharply increase, which, under a certain combination of temperature–time parameters, evolve into the σ phase with low coherence with the γ-solid solution. However, this phenomenon has little effect on the mechanical properties at room temperature.