Tensile Properties and Deformation Mechanisms of Haynes 282 at Various Temperatures

The effect of temperature on the deformation mechanism and corresponding tensile properties of Haynes 282 is investigated in the temperature range from room temperature to 800 °C. It is found that below 600 °C, the yield strength remains basically unchanged with increasing temperature, while, above the temperature, a dramatic decrease in the yield strength is observed. Transmission electron microscopy observations on the slightly deformed specimens reveal that, for the experimental alloy, the plastic deformation is accomplished predominantly by pairs of a/2〈101〉 dislocation shearing through γ′ precipitates at temperatures between room temperature and 600 °C and by individual matrix dislocation bypassing γ′ precipitates above 760 °C, whereas at temperatures between the two temperatures, anti-phase boundary shearing and stacking fault shearing as well as Orowan looping operate simultaneously during the initial plastic deformation. Based on the experimental observations, it is deemed that the transitions in the deformation mechanisms account for the variation of the yield strength of the experimental alloy with temperature.