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Search Publications by: Peter Bradley (Fed)

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Displaying 1 - 25 of 50

Effects of mechanical deformation on dislocation density and phase partitioning in 4130 steel

August 22, 2023
Author(s)
Zack Buck, Matthew Connolly, May Ling Martin, Damian Lauria, Jason Killgore, Peter Bradley, Yan Chen, Ke An, Andrew Slifka
Interrupted tensile tests were performed on an AISI 4130 pressure vessel steel and investigated by neutron diffraction and scanning microscopy techniques. Analysis of the neutron diffraction patterns reveal a partitioning of ferrite and martensite phases

Determining Steel Weld Qualification and Performance for Hydrogen Pipelines: Phase I Report

May 23, 2023
Author(s)
Matthew Connolly, May Ling Martin, Zack Buck, Newell Moser, Enrico Lucon, Damian Lauria, Peter Bradley, Andrew Slifka, Robert Amaro
This report details the results of Phase I of the DOT/PHMSA sponsored work on "Determining Steel Weld Qualification and Performance for Hydrogen Pipelines". In this work, the goals of Phase I were 1) to perform a literature review of steel weld

Strain-life performance in hydrogen of DOT pressure vessel steel

November 7, 2022
Author(s)
May Ling Martin, Peter Bradley, Damian Lauria, Robert L. Amaro, Matthew Connolly, Andrew Slifka
Strain-life testing of a 4130 pressure vessel steel was conducted in air and in a high-pressure gaseous-hydrogen environment. Hydrogen causes an order of magnitude decrease in lifetime compared to in-air performance at the same strain-amplitudes. This

High Energy X-Ray Diffraction and Small-Angle Scattering Measurements of Hydrogen Fatigue Damage in AISI 4130 Steel

June 4, 2022
Author(s)
Matthew Connolly, May Ling Martin, Peter Bradley, Damian Lauria, Andrew Slifka, Jun-Sang Park, Robert Amaro, Jonathan Almer
Accurate lifetime predictions are critical for repurposing existing pipelines for hydrogen transmission as well as for developing novel steels which are minimally susceptible to lifetime degradation by hydrogen. Ultimately, lifetime prediction models

Evaluating a Natural Gas Pipeline Steel for Blended Hydrogen Service

March 19, 2022
Author(s)
May Ling Martin, Matthew Connolly, Zack Buck, Peter Bradley, Damian Lauria, Andrew Slifka
An X70 natural gas pipeline steel that is being considered for blended natural gas/hydrogen gas service was evaluated in a high-pressure hydrogen gas environment. Fracture toughness testing and fatigue crack growth rate testing were conducted according to

Materials Testing in Hydrogen

November 30, 2021
Author(s)
Matthew Connolly, May Ling Martin, Damian Lauria, Peter Bradley, Zack Buck, Andrew Slifka, Robert L. Amaro

Experimental study of shear and tensile properties of LIGA Ni-Fe and Ni-Co alloys at quasi-static and intermediate strain rates

April 1, 2021
Author(s)
Li-Anne Liew, David T. Read, May Martin, Todd R. Christenson, Peter E. Bradley, Nicholas Barbosa, Frank W. DelRio, John T. Geaney, Jeffrey Smyth
We report the in-plane shear properties, to fracture, of 200 um-thick LIGA nanocrystalline Ni- 10%Fe and micrograined Ni-10%Co. Planar simple shear specimens were designed, fabricated and pulled to fracture using a miniature commercial tension test stage

Characteristics and Mechanisms of Hydrogen-Induced Quasi-Cleavage Fracture of Lath Martensitic Steel

January 10, 2021
Author(s)
Lawrence Cho, Peter E. Bradley, Damian S. Lauria, May L. Martin, Matthew J. Connolly, Jake Benzing, Eun Jung Seo, Kip O. Findley, John G. Speer, Andrew J. Slifka
This study presents an in-depth characterization of the microstructures, crystallographic orientations, and dislocation characteristics beneath the hydrogen-induced quasi-cleavage features of an as-quenched, lath martensitic (') 22MnB5 steel. The fracture

Elastic-plastic properties of mesoscale electrodeposited LIGA nickel alloy films: microscopy and mechanics

November 22, 2020
Author(s)
Li-Anne Liew, David T. Read, May Martin, Frank W. DelRio, Peter E. Bradley, Nicholas Barbosa, Todd R. Christenson, John T. Geaney
The elastic-plastic properties of mesoscale electrodeposited LIGA Ni alloy specimens are investigated as a function of specimen size, strain rate, and material composition. Two material compositions are studied: a high-strength fine-grained Ni-Fe alloy and

HEXRD Measurement of Strain and Dislocation Density ahead of Crack Tips Grown in Hydrogen

September 13, 2019
Author(s)
Matthew J. Connolly, May L. Martin, Peter E. Bradley, Damian S. Lauria, Andrew J. Slifka, Jun Sang Park, Robert Amaro
The deformation fields near fatigue crack tips grown in hydrogen and in air were measured using high-energy x-ray diffraction. A larger magnitude of elastic strain was observed in the hydrogen case compared to the air case. The magnitude of elastic strain

Demonstration of a Chamber for Strain Mapping of Steel Specimens Under Mechanical Load in a Hydrogen Environment by Synchrotron Radiation

June 4, 2018
Author(s)
Matthew J. Connolly, Peter E. Bradley, Damian S. Lauria, Andrew J. Slifka, Elizabeth S. Drexler
We present a demonstration of a chamber for diffraction measurements of lattice strain for specimens in hydrogen gas under mechanical load. The chamber is suitable for static and cyclic mechanical loading. Synchrotron x-ray radiographs of a fatigue crack

In Situ Neutron Transmission Bragg Edge and Synchrotron X-Ray Measurement of Strain Fields Near Fatigue Cracks Grown in Hydrogen

April 18, 2018
Author(s)
Matthew J. Connolly, Peter E. Bradley, Damian S. Lauria, Andrew J. Slifka, Elizabeth S. Drexler
The embrittlement and enhanced fatigue crack growth rate of metals in the presence of hydrogen is a long-standing problem. In an effort to determine the dominate damage mechanism behind hydrogen assisted fatigue crack growth, we performed High-Energy X-ray

Chamber for Mechanical Testing in H2 with Observation by Neutron Scattering

June 1, 2017
Author(s)
Matthew J. Connolly, Peter E. Bradley, Andrew J. Slifka, Elizabeth S. Drexler
A gas-pressure chamber has been designed, constructed, and tested at a moderate pressure (3.4 MPa, 500 psi) and has the capability of mechanical loading of steel specimens for neutron scattering measurements. The chamber will allow a variety of in situ

Design and Analysis of a 150 K Cascade Joule-Thomson Microcooler

June 9, 2014
Author(s)
Ray Radebaugh, Peter E. Bradley, Collin J. Coolidge, Ryan J. Lewis, Y.C. Lee
Lightweight and compact microcoolers are needed for advanced, hand-held infrared systems. A temperature of 150 K is adequate for high sensitivity with some of the latest IR detectors, which simplifies the cooling requirements compared to 80 K detectors

Properties of Selected Materials at Cryogenic Temperatures

June 17, 2013
Author(s)
Peter E. Bradley, Ray Radebaugh
The design of systems for operation at cryogenic temperatures requires the use of material properties at these low temperatures. The properties at cryogenic temperatures can be much different than the room-temperature values. In addition, some properties