Comparative Thermal Aging Effects on PM-HIP and Forged Inconel 690

Autor: Keyou Mao, Nathaniel L. Vas, Nathan B. Cain, David Gandy, Alexander L. Bullens, Esteban Bautista, Janelle P. Wharry, Elizabeth H. Jaye
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: JOM (1989)
Popis: This study compares thermal aging effects in Inconel 690 (IN690) produced by forging and powder metallurgy with hot isostatic pressing (PM-HIP). Isothermal aging is carried out over 400-800°C for up to 1000 h and then metallography and nanoindentation are utilized to relate grain microstructure with hardness and yield strength. The PM-HIP IN690 maintains a constant grain size through all aging conditions, while the forged IN690 exhibits limited grain growth at the highest aging temperature and longest aging time. The PM-HIP IN690 exhibits comparable mechanical integrity as the forged material throughout aging: hardness and yield strength are unchanged with 100 h aging, but increase after 1000 h aging at all temperatures. In both the PM-HIP and forged IN690, the Hall-Petch relationship for Ni-based super-alloys predicts yield strength for 0-100 h aged specimens, but underestimates yield strength in the 1000 h aged specimens because of thermally induced precipitation.
Databáze: OpenAIRE