Title: Texture evolution and microcracking mechanisms in as-extruded and cross-rolled conditions of a 14YWT nanostructured ferritic alloy

Abstract

Cr-stabilized nanostructured ferritic alloys (NFAs), dispersion strengthened by an ultra-high density of nanooxides, are attractive candidates for many nuclear energy applications due to their high-temperature strength, in-service stability and remarkable irradiation tolerance. However, typical NFA deformation processing paths lead to crystallographic texturing, formation of brittle microstructures and low toughness orientations, making fabricating components very difficult. In this paper, we characterize the dislocation-mediated deformation mechanisms that lead to the brittle texture component. The as-extruded bar is less brittle than the cross-rolled plate, which contains a large population of pre-existing cleavage microcracks. More generally, deformed ODS/NFAs are most often textured and have anisotropic low toughness orientations, even absent microcracks. However, cross-rolling produces a very high volume fraction of a plate normal {001}<110>-texture component, which constitutes the brittle cleavage system in iron. Finally, microcracks propagate along {001} low angle deformation induced subgrain boundaries in <110> directions after nucleating by the Cottrell mechanism.

Authors:

Pal, S.  ^[1];

• Search DOE PAGES for author "Pal, S."
• Search DOE PAGES for ORCID "0000-0001-6851-1649"

Alam, M. E. ^[1]; Maloy, S. A.  ^[2];

• Search DOE PAGES for author "Maloy, S. A."
• Search DOE PAGES for ORCID "0000-0001-8037-1319"

Hoelzer, D. T.  ^[3];

• Search DOE PAGES for author "Hoelzer, D. T."
• Search DOE PAGES for ORCID "0000-0001-9366-9958"

Odette, G. R. ^[1]

---

+ Show Author Affiliations

1. Univ. of California, Santa Barbara, CA (United States). Materials Dept.
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

Publication Date:

Wed Apr 11 00:00:00 EDT 2018

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of California, Santa Barbara, CA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5); National Science Foundation (NSF); USDOE Office of Nuclear Energy (NE)

OSTI Identifier:

1471888

Alternate Identifier(s):

OSTI ID: 1548479

Grant/Contract Number:  

AC05-00OR22725; FG03-94ER54275; 00119430 8-442520-59048; LANL8-442550-59434

Resource Type:

Accepted Manuscript

Journal Name:

Acta Materialia

Additional Journal Information:

Journal Volume: 152; Journal ID: ISSN 1359-6454

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; nanostructured ferritic alloy; ODS steel; texture; microcracking; deformation processing