Creep ductility of 1Cr1Mo1/4V low alloy forging and casting steels

1Cr1Mo1/4V low alloy forging and casting steels exhibited considerable secondary and tertiary stages in the creep tests conducted in the temperature range between 813 and 873 K (500 and 600 °C). The primary stage, though present, was rather negligible in higher-temperature ranges. Casting steel showed wedge-type cavities which grew as cracks along the grain boundaries. In the case of forging steel, the voids, which developed in the tertiary stage of creep deformation, were elliptical and flat. Tertiary creep deformation and creep ductility of the two steels have been analysed based on the type of voids developed in the tertiary stage.