Microstructural and Microchemical Characterization of Dual Step Aged Alloy X-750 and its Relationship to Environmentally Assisted Cracking.

Young, G. A. ; Lewis, N. ; Hanson, M. ; Matuszyk, W. ; Wiersma, B. ; Gonzalez, S. C.

Technical Information Center Oak Ridge Tennessee

关键词: Alloys;    Crack propagation;    Carbides;    Desorption;    Fractures;   

RP-ID  :  DE2004821679

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

When exposed to deaerated high purity water, Alloy X-750 is susceptible to both high temperature (& 249 degrees C) intergranular stress corrosion cracking (IGSCC) and intergranular low temperature (& 149 degrees C) fracture (LTF). However, the microstructural and microchemical factors that govern environmentally assisted cracking (EAC) susceptibility are poorly understood. The present study seeks to characterize the grain boundary microstructure and microchemistry in order to gain a better mechanistic understanding of stress corrosion crack initiation, crack growth rate, and low temperature fracture. Light microscopy, scanning electron microscopy, transmission electron microscopy, orientation imaging microscopy, scanning Auger microscopy, and thermal desorption spectroscopy were performed on selected heats of Alloy X-750 AH.