摘要
0.02%(mass fraction) Mg and 0.02% Ce were added into nickel-base superalloy, K465, in order to study their effect on microstructures and mechanical properties. The results showed that without addition of Mg and Ce, the grain boundaries was flat, the MC carbide precipitate was noncontinuous with particle shape. With 0.02% Mg addition the MC carbide tended to have tiny granular and blocky morphology, while it had a cursive script-like morphology with 0.02% Ce addition. It was also shown that without any addition of Mg and Ce, the room temperature properties, average tensile strength (σb) and yield strength (σ0.2) were 960 and 790 MPa, the creep rupture life under the condition of 1248 K, 230 MPa was 28.1 h. With the addition of 0.02% Mg, the room temperature properties, average tensile strength and yield strength had a certain enhancement, the creep rupture life (1248 K, 230 MPa) was up to 66.7 h. When the Ce addition was 0.02%, average tensile strength and yield strength were up to 1020～1030 MPa and 855～885 MPa, respectively, but the average elongation percentage fell down to 3.0%, only reaching the required value. The most expressive thing was that the creep rupture life (1248 K, 230 MPa) was only 17.25～18.77 h, far below the required value.
0.02%(mass fraction) Mg and 0.02% Ce were added into nickel-base superalloy, K465, in order to study their effect on microstructures and mechanical properties. The results showed that without addition of Mg and Ce, the grain boundaries was flat, the MC carbide precipitate was noncontinuous with particle shape. With 0.02% Mg addition the MC carbide tended to have tiny granular and blocky morphology, while it had a cursive script-like morphology with 0.02% Ce addition. It was also shown that without any addition of Mg and Ce, the room temperature properties, average tensile strength (σb) and yield strength (σ0.2) were 960 and 790 MPa, the creep rupture life under the condition of 1248 K, 230 MPa was 28.1 h. With the addition of 0.02% Mg, the room temperature properties, average tensile strength and yield strength had a certain enhancement, the creep rupture life (1248 K, 230 MPa) was up to 66.7 h. When the Ce addition was 0.02%, average tensile strength and yield strength were up to 1020～1030 MPa and 855～885 MPa, respectively, but the average elongation percentage fell down to 3.0%, only reaching the required value. The most expressive thing was that the creep rupture life (1248 K, 230 MPa) was only 17.25～18.77 h, far below the required value.
