Effect of Ta content on mechanical properties of FGH4098 powder superalloy
XING Peng-yu1,2， ZHANG Yi-wen1,2， JIA Jian1,2
1High Temperature Material Institute, Central Iron and Steel Research Institute, Beijing 100081, China,2 Beijing Key Laboratory of Advanced High Temperature Materials, Beijing 100081, China
Abstract：The impact toughness (room temperature), tensile properties (room temperature, 650 ℃, 750 ℃), durability (650 ℃, 750 ℃) and fatigue crack growth rate at 650 ℃ of FGH4098 alloy with different Ta contents were studied. According to the impact, tensile and durability fracture of alloys with different Ta content, as well as the microstructure of two different aging treatment (650 ℃/3 000 h and 750 ℃/3 000 h), the effect of Ta content on the mechanical properties of the alloy was analyzed. The result shows that excessive Ta content decreases the impact toughness badly and alloys with 1.2%-3.6% Ta content (mass percent) can maintain better impact toughness. With the increase of Ta content, the tensile strength at room temperature and high temperature increase, and alloy with 1.2%-3.6% Ta has the best tensile ductility. With the increase of Ta content, the durable life of the alloy at 650 ℃ is obviously increased. However, at 750 ℃, excessive Ta will promote the precipitation of TCP phase, seriously affecting the high-temperature durability of the alloy. When Ta content is 2.4%-3.6%, the durability of the alloy is the best. With the increase of Ta content, the fatigue crack growth rate of alloy decreases gradually at 650 ℃. In conclusion, FGH4098 alloy with Ta content between 2.4%-3.6% has the best comprehensive mechanical properties.
2019, Vol. 29 
