麻豆影音

Skip to main content
SHARE
Publication

Effect of heterogeneous microstructure on the tensile and creep performances of cast Haynes 282 alloy

Publication Type
Journal
Journal Name
Materials Science and Engineering: A
Publication Date
Page Number
142099
Volume
828

Precipitation-strengthened Ni-based superalloys are leading candidate materials for advanced ultra-supercritical (A-USC) plants with steam conditions up to 760 掳C (1400 掳F) and 35 MPa (5 ksi). This study evaluates representative specimens from a large casting of Haynes 282 to study the effect of microstructural heterogeneity on the mechanical behavior of this alloy. The tensile test results of cast Haynes 282 over the temperature range 20鈥�816 掳C exhibited lower tensile strength and ductility in comparison with the reference wrought Haynes 282. However, the creep rupture tests of the cast alloy below 704鈥�788 掳C and 190鈥�431 MPa presented a similar stress-Larson-Miller parameter to that of the wrought material. Microstructural and dislocation characterizations using scanning electron microscopy, conventional transmission electron microscopy, and scanning transmission electron microscopy in conjunction with energy dispersive X-ray spectroscopy were performed to understand the microstructural evolution before and after the mechanical tests. The heterogeneous microstructures of the cast Haynes 282 material, including the coarse grains, potential casting defects, and a bimodal size distribution of 纬鈥� precipitates, were detrimental to the tensile behavior, whereas the coarse-scale grains had a positive effect on the creep performance because diffusional creep was the dominant creep mechanism.