Title: Cold spray manufacturing of oxide-dispersion strengthened (ODS) steels using gas-atomized and ball-milled 14YWT powders

Abstract

The cold spray deposition process has been investigated for the manufacture of 14YWT oxide-dispersion strengthened (ODS) steel, a nanostructured ferritic alloy (NFA), using gas-atomized and ball-milled feedstock powders. Cold spraying of the gas-atomized powder resulted in a thick dense deposit, but annealing them above 900 °C induced grain growth and heterogeneous precipitation of nanoparticles, thus resulting in lower hardness (~ 170 HV) compared to 14YWT ODS steel manufactured by the conventional method. The ball-milled powder (Fe-14Cr-3W-0.4Ti-0.2Y-0.125O) was cryomilled in liquid N₂ to achieve small particle sizes followed by annealing in a H₂/Ar environment at 1000 °C and 1100 °C to reduce the hardness from ~ 8 GPa to ~ 5 GPa. Both smaller particle sizes and lower hardness of annealed powders made them amenable to the cold spray deposition process, resulting in thick and dense deposits, while retaining the favorable fully solutionized microstructure of the ball-milled powders. The microstructure of the as-deposited ODS exhibited very fine grain sizes (50–250 nm) with a uniform dispersion of Y-Ti-O nanoprecipitates in the ferritic steel matrix. The hardness values of the cold spray deposits using the powders annealed at 1000 °C and 1100 °C was 770 HV and 496 HV, respectively. Post-heat treatment ofmore » the as-deposited material up to 1100 °C showed a high-density microstructure with uniformly dispersed nanoscale oxide particles. The hardness of the annealed deposits up to 1000 °C had a notably higher hardness than bulk 14YWT ODS steel manufactured by conventional methods. The study demonstrates that cold spray deposition of the microstructurally-tailored feedstock powders can be used to successfully manufacture ODS steel with microstructure and properties comparable to those produced by the conventional methods, while providing for an attractive option for the more rapid and cost-effective manufacturing of ODS steel cladding tubes.« less

Authors:

Yeom, Hwasung  ^[1];

• Search DOE PAGES for author "Yeom, Hwasung"
• Search DOE PAGES for ORCID "0000-0002-3798-2795"

Hoelzer, David  ^[2];

• Search DOE PAGES for author "Hoelzer, David"
• Search DOE PAGES for ORCID "0000-0001-9366-9958"

Maloy, Stuart  ^[3];

• Search DOE PAGES for author "Maloy, Stuart"
• Search DOE PAGES for ORCID "0000-0001-8037-1319"

Sridharan, Kumar ^[1]

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+ Show Author Affiliations

1. University of Wisconsin-Madison, WI (United States)
2. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
3. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Publication Date:

Mon Dec 05 00:00:00 EST 2022

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Idaho National Laboratory (INL), Idaho Falls, ID (United States)

Sponsoring Org.:

USDOE Office of Nuclear Energy (NE), Nuclear Energy University Program (NEUP); USDOE

OSTI Identifier:

1985356

Alternate Identifier(s):

OSTI ID: 1908916

Grant/Contract Number:  

NE0008682; 19–2843

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Nuclear Materials

Additional Journal Information:

Journal Volume: 574; Journal ID: ISSN 0022-3115

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; Oxide dispersion strengthened steel; 14YWT; Cold spray deposition technology; Powder engineering