Alloy selection and alloy design both require consideration of an array of material attributes, including in-service properties, weldability and fabricability. Critical properties of advanced wrought superalloys for g...Alloy selection and alloy design both require consideration of an array of material attributes, including in-service properties, weldability and fabricability. Critical properties of advanced wrought superalloys for gas turbine applications include high temperature strength, thermal stability, oxidation resistance and fatigue resistance. In this paper, the properties of twelve wrought solid-solution-strengthened and six age-hardenable superalloys are compared. Weldability is an important attribute and can be a major limiting factor in the use of certain alloys. Weldability test methods are discussed and the resistance of alloys to solidification cracking and strain-age cracking is compared. The use of weldability testing in the development of modern wrought su-peralloys is discussed with several examples cited. Finally, alloy selection for gas turbine components is outlined, taking into account both alloy properties and fabricability.展开更多
TEM study was made to explore the mechanism of the strain-age hardening of initially-dis- ordered (Co_(78)Fe_(22))_3V,which was found to be attributed to the formation of a special disloca- tion-stacking fault configu...TEM study was made to explore the mechanism of the strain-age hardening of initially-dis- ordered (Co_(78)Fe_(22))_3V,which was found to be attributed to the formation of a special disloca- tion-stacking fault configuration in company with disorder-order transformation-disloca- tions extended to stacking faults on{111}planes and got connected with each other through partial dislocation reaction at intersections of{111}planes,leading to dense networks with cells bounded by stacking fault tetrahedrons.The results also indicated that ordered (Co_(78)Fe_(22))_3V has very low stacking fault energy on{111}planes and relative high and isotropie antiphase boundary energy,which implies that it is most likely to be Lomer-Cottrell locks,not Kear-Wilsdof locks,that are responsible for the high strength at high temperatures of this alloy.展开更多
文摘Alloy selection and alloy design both require consideration of an array of material attributes, including in-service properties, weldability and fabricability. Critical properties of advanced wrought superalloys for gas turbine applications include high temperature strength, thermal stability, oxidation resistance and fatigue resistance. In this paper, the properties of twelve wrought solid-solution-strengthened and six age-hardenable superalloys are compared. Weldability is an important attribute and can be a major limiting factor in the use of certain alloys. Weldability test methods are discussed and the resistance of alloys to solidification cracking and strain-age cracking is compared. The use of weldability testing in the development of modern wrought su-peralloys is discussed with several examples cited. Finally, alloy selection for gas turbine components is outlined, taking into account both alloy properties and fabricability.
文摘TEM study was made to explore the mechanism of the strain-age hardening of initially-dis- ordered (Co_(78)Fe_(22))_3V,which was found to be attributed to the formation of a special disloca- tion-stacking fault configuration in company with disorder-order transformation-disloca- tions extended to stacking faults on{111}planes and got connected with each other through partial dislocation reaction at intersections of{111}planes,leading to dense networks with cells bounded by stacking fault tetrahedrons.The results also indicated that ordered (Co_(78)Fe_(22))_3V has very low stacking fault energy on{111}planes and relative high and isotropie antiphase boundary energy,which implies that it is most likely to be Lomer-Cottrell locks,not Kear-Wilsdof locks,that are responsible for the high strength at high temperatures of this alloy.
