题目：Strain Localisation and Hydrogen Embrittlement of Nickel-Based Superalloys (镍基高温合金应变局域化和氢脆行为研究)

时间：2018年6月13日 14:00-15:00

地点：密西根学院(龙宾楼) 415B

邀请人：张超群博士（汽车工程研究院）

Biography

Dr. Zhenbo Zhang received BEng and MEng from Chongqing University and Institute of 
Metal Research CAS, respectively. After finishing PhD in Risoe National Lab, Technical University of Denmark in Dec. 2014, he joined in the BP International Centre for Advanced Materials, University of Manchester as a research associate. His research interest and expertise is using advanced microstructural and mechanical characterisation techniques to understand the microstructure-property-performance relationships in engineering alloys, including Ni-based superalloys, steels and Ti alloys. His research experience involves several aspects, including microstructure evolution during plastic deformation and subsequent recovery and recrystallization, performance of Ni-based superalloys and Ti alloys in hydrogenating environment and related mechanism for hydrogen embrittlement, fatigue behavior of ultrafine grained biomedical Ti alloy, etc. He has published more than 20 papers in international journals including Acta Materialia, Philosophical Magazine, Metallurgical Materials Transaction A, Scripta Materialia, etc., and serves as a reviewer for international journals like Scripta Materialia, Materials Design, Journal of Materials Science etc.

Abstract

Nickel-based superalloys used in the oil & gas deep wells suffer from hydrogen induced embrittlement. Current lack of mechanistic understanding of the hydrogen embrittlement (HE) of superalloys makes it difficult to optimise the alloy chemistry and microstructure to reduce the HE susceptibility. In this study, the roles of strain localisation, twin boundary and various precipitates in HE of superalloys 718 and 945X are explored in details. The HE mechanism of nickel-based superalloys is proposed, and strategies to enhance their performance in hydrogenating environment are discussed.