Host: The Japan Society of Mechanical Engineers
Name : International Conference on Power Engineering-2021(ICOPE-2021)
Date : October 17, 2021 - October 21, 2021
Alloy Hastelloy-X was fabricated by a typical metal additive manufacturing process-selective laser melting (SLM), and the effects of heat treatment processes, forming orientation/position, powder’s O and N composition on microstructures and tensile properties of this alloy were investigated. The metallographic analysis results show both heat treatment (HT) and hot isostatic pressing (HIP) can facilitate the grains transformation from columnar to equiaxed ones and homogenize the microstructure, while HIP can further close cracks, pores and lead to precipitates formation along the grain boundary. As a result, HTed and HITed alloy have a higher ductility but a lower strength compared with as-deposited ones, for especially the HIPed alloy has an elongation up to 50%, far beyond the wrought HX specification value (12%). It is also revealed that both vertical and horizontal formed SLM alloy can reach to wrought HX’s tensile properties (refer to AMS 5536), but the horizontal one has a better ductility and slightly lower yield strength due to its grain orientation distribution. In order to keep the alloys’ strength and ductility reach to requirements of AMS 5536, the O composition should be below 100 ppm and N should be below 80 ppm
