Title: Spatially resolved texture and microstructure evolution of additively manufactured and gas gun deformed 304L stainless steel investigated by neutron diffraction and electron backscatter diffraction

Abstract

In this study, we report the characterization of a 304L stainless steel cylindrical projectile produced by additive manufacturing. The projectile was compressively deformed using a Taylor Anvil Gas Gun, leading to a huge strain gradient along the axis of the deformed cylinder. Spatially resolved neutron diffraction measurements on the HIgh Pressure Preferred Orientation time-of-flight diffractometer (HIPPO) and Spectrometer for Materials Research at Temperature and Stress diffractometer (SMARTS) beamlines at the Los Alamos Neutron Science CEnter (LANSCE) with Rietveld and single-peak analysis were used to quantitatively evaluate the volume fractions of the α, γ, and ε phases as well as residual strain and texture. The texture of the γ phase is consistent with uniaxial compression, while the α texture can be explained by the Kurdjumov–Sachs relationship from the γ texture after deformation. This indicates that the material first deformed in the γ phase and subsequently transformed at larger strains. The ε phase was only found in volumes close to the undeformed material with a texture connected to the γ texture by the Shoji–Nishiyama orientation relationship. This allows us to conclude that the ε phase occurs as an intermediate phase at lower strain, and is superseded by the α phase when strainmore » increases further. Furthe, we found a proportionality between the root-mean-squared microstrain of the γ phase, dominated by the dislocation density, with the α volume fraction, consistent with strain-induced martensite α formation. In conclusion, knowledge of the sample volume with the ε phase from the neutron diffraction analysis allowed us to identify the ε phase by electron back scatter diffraction analysis, complementing the neutron diffraction analysis with characterization on the grain level.« less

Authors:

Takajo, Shigehiro ^[1]; Brown, Donald William  ^[2];

• Search DOE PAGES for author "Brown, Donald William"
• Search DOE PAGES for ORCID "0000-0003-4565-8212"

Clausen, Bjorn  ^[2];

• Search DOE PAGES for author "Clausen, Bjorn"
• Search DOE PAGES for ORCID "0000-0003-3906-846X"

Gray III, George Thompson  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-4540-7061"

Knapp, Cameron M.  ^[2];

• Search DOE PAGES for author "Knapp, Cameron M."
• Search DOE PAGES for ORCID "0000-0001-8775-7660"

Martinez, Daniel Tito ^[2]; Trujillo, Carl Patrick ^[2]; Vogel, Sven C.  ^[2]

• Search DOE PAGES for author "Vogel, Sven C."
• Search DOE PAGES for ORCID "0000-0003-2049-0361"

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+ Show Author Affiliations

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); JFE Steel Corporation, Kurashiki (Japan)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

Mon Apr 30 00:00:00 EDT 2018

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1440473

Report Number(s):

LA-UR-17-25178
Journal ID: ISSN 0885-7156; applab

Grant/Contract Number:  

AC52-06NA25396

Resource Type:

Accepted Manuscript

Journal Name:

Powder Diffraction

Additional Journal Information:

Conference: 66. Denver X-Ray Conference, Big Sky, MT (United States), 31 Jul - 4 Aug 2017; Journal ID: ISSN 0885-7156

Publisher:

Cambridge University Press

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; electron backscatter diffraction; neutron diffraction; 304L stainless steel