Role of oxygen in enhanced fatigue cracking in a PM Ni-based superalloy: Stress assisted grain boundary oxidation or dynamic embrittlment?

Affiliation of Author(s):能源与动力学院

Journal:CORROSION SCIENCE

Key Words:Ni-based superalloys Fatigue crack initiation Fatigue crack propagation Stress assisted grain boundary oxidation Dynamic embrittlement

Abstract:The role of oxygen in enhanced fatigue cracking in an advanced Ni-based superalloy for turbine disc application has been evaluated in fatigue crack initiation and propagation stages along with static oxidation tests. It is found that the grain boundary oxide intrusion has a layered structure. The microstructure- and deformation-dependent grain boundary oxidation dominates the fatigue crack initiation and early propagation processes. As the crack propagates, this contribution arising from oxidation damage may gradually be overtaken by dynamic embrittlement processes until the mechanical damage outstrips the oxygen-related damage, resulting in a transition from intergranular to transgranular crack propagation.

ISSN No.:0010-938X

Translation or Not:no

Date of Publication:2018-07-15

Co-author:Proprentner, D.,Callisti, M.,Shollock, B.,Hu Xuteng,syd,Reed, P. A. S.

Correspondence Author:jiangrong

Date of Publication:2018-07-15