The effect of carbide solvation on the γ/γ+δ boundary temperature Tδ and the equilibrium relationship between the alloying elements at the γ/γy +δ boundary in austenitic steels at high temperature have been stu...The effect of carbide solvation on the γ/γ+δ boundary temperature Tδ and the equilibrium relationship between the alloying elements at the γ/γy +δ boundary in austenitic steels at high temperature have been studied, and the variation of the ferrite volume fraction with temperature in α+ γ dual phase steel has been investigated. The relative expressions are derived from many experimental results, which provides a basis for quantitative calculation, composition design, determination of the working processes,and prediction of the mechanical properties and the structure of the austenitic steels.展开更多
The relationship between the γ/(γ+δ) boundary temperature Tδ of austenitic steels and the equivalent weights of [Crl and [Ni] and the variation rule of the δ phase volume with the temperature are studied With th...The relationship between the γ/(γ+δ) boundary temperature Tδ of austenitic steels and the equivalent weights of [Crl and [Ni] and the variation rule of the δ phase volume with the temperature are studied With the aid of computer,the regressives expression derived from the experimental results are Tδ(℃) = T4 -21.2[Cr] +15.8[Ni]-223. Vδ(%)=0.715 exp 0.015(T-Tδ).展开更多
Micro-alloying of Mg,ranged from 30 to 70 ppm,may improve the high temperature ductility,stress rupture,especially,certain important mechanical properties,such as cyclic stress rupture,creep/fatigue interaction and cr...Micro-alloying of Mg,ranged from 30 to 70 ppm,may improve the high temperature ductility,stress rupture,especially,certain important mechanical properties,such as cyclic stress rupture,creep/fatigue interaction and crack propagation rate.The quantity, morphology and distribution of δ-phase may obviously influence the notched cyclic stress rup- ture life.The relevant microstructure shows that the Mg may also influence to certain extent on the feature of δ-phase.Thus,to keep the Mg and δ-phase under control may further im- prove the mechanical properties of alloy GH169.展开更多
U 10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal structures.The collected diffraction data are processed using Rietveld' s profile technique (w...U 10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal structures.The collected diffraction data are processed using Rietveld' s profile technique (with program“ Fullprof ”). Four phases,α-U,δ, γand α Zr, in the alloy at room temperature and the corresponding volume fractions as well their structural parameters are obtained from the data analysis, For the δ-phase, a partially ordered unusual hexagonal structure of the modified C32(AlB2) type is confirmed.展开更多
文摘The effect of carbide solvation on the γ/γ+δ boundary temperature Tδ and the equilibrium relationship between the alloying elements at the γ/γy +δ boundary in austenitic steels at high temperature have been studied, and the variation of the ferrite volume fraction with temperature in α+ γ dual phase steel has been investigated. The relative expressions are derived from many experimental results, which provides a basis for quantitative calculation, composition design, determination of the working processes,and prediction of the mechanical properties and the structure of the austenitic steels.
文摘The relationship between the γ/(γ+δ) boundary temperature Tδ of austenitic steels and the equivalent weights of [Crl and [Ni] and the variation rule of the δ phase volume with the temperature are studied With the aid of computer,the regressives expression derived from the experimental results are Tδ(℃) = T4 -21.2[Cr] +15.8[Ni]-223. Vδ(%)=0.715 exp 0.015(T-Tδ).
文摘Micro-alloying of Mg,ranged from 30 to 70 ppm,may improve the high temperature ductility,stress rupture,especially,certain important mechanical properties,such as cyclic stress rupture,creep/fatigue interaction and crack propagation rate.The quantity, morphology and distribution of δ-phase may obviously influence the notched cyclic stress rup- ture life.The relevant microstructure shows that the Mg may also influence to certain extent on the feature of δ-phase.Thus,to keep the Mg and δ-phase under control may further im- prove the mechanical properties of alloy GH169.
文摘U 10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal structures.The collected diffraction data are processed using Rietveld' s profile technique (with program“ Fullprof ”). Four phases,α-U,δ, γand α Zr, in the alloy at room temperature and the corresponding volume fractions as well their structural parameters are obtained from the data analysis, For the δ-phase, a partially ordered unusual hexagonal structure of the modified C32(AlB2) type is confirmed.
