| Title |
Effect of γ' Precipitates and Y2O3 Dispersoids on High Temperature Creep in Mechanically alloyed Ni - Cr - W Alloy |
| Authors |
권숙인(S . I . Kwun); 조준식(J . S . Cho) |
| Abstract |
The effects of γ` precipitates and Y₂O₃, dispersoids on high temperature tensile and creep properties of mechanically alloyed Ni-20Cr-4W alloy were studied. The zone annealing was performed to increase grain size and grain aspect ratio. The zone annealing method was found very useful to increase high temperature strength and creep resistance. The addition of Y₂O₃into Ni-20Cr-4W alloy not only gave this alloy dispersion hardening, but also improved thermal stability of γ` precipitates at high temperature. Up to 950℃, γ` precipitates contributed to high temperature properties more efficiently than Y₂O₃dispersoids. However, the contribution of Y₂O₃to high temperature strength was greater in creep than in high temperature tension. The mechanically alloyed Ni-20Cr-4W alloy showed the creep threshold stress. |