EPMA and TEM characterization of intergranular tellurium corrosion of Ni–16Mo–7Cr–4Fe superalloy. (August 2015)

• Record Type: Journal Article
• Authors: Cheng, Hongwei; Leng, Bin; Chen, Kai; Jia, Yanyan; Dong, Jiasheng; Li, Zhijun; Zhou, Xingtai
• Is Part Of: Corrosion science. Volume 97(2015)
• Page Start: 1
• Page End: 6
• Publication Date: 2015-08
• Subjects: A. Superalloy -- C. Intergranular corrosion -- C. Reactor conditions; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2015.04.017
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Te preferentially diffuses into the Ni-based alloy along grain boundaries at 800 °C. Te can react with Cr to form cubic structure CrTe at both grain boundaries and intergranular carbide/matrix interfaces. The CrTe is possible to induce intergranular cracking in the alloy. Abstract: The corrosion behavior of a Ni–16Mo–7Cr–4Fe alloy was investigated in a tellurium (Te) vapor atmosphere at 800 °C. Te was identified via electron probe microanalysis at the grain boundary regions of the corroded alloy. The morphology, chemical composition, and crystalline structure of those areas were characterized in a transmission electron microscope. Chromium tellurides were observed at both grain boundaries and intergranular carbide–matrix interfaces. Based on the results, the mechanism of intergranular Te corrosion and its possible correlation with intergranular cracking is discussed.