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Search Publications by: Andrew Slifka (Fed)

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Displaying 1 - 25 of 76

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

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

Hydrogen embrittlement in ferritic steels

October 6, 2020
Author(s)
May L. Martin, Matthew J. Connolly, Frank W. DelRio, Andrew J. Slifka
The deleterious effects of hydrogen on the physical properties of metals have been known for over a century. Despite extensive work over that time period, there are still significant questions related to the “hydrogen embrittlement” of ferritic steels due

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

Fatigue Testing of Pipeline Welds and Heat-Affected Zones in Pressurized Hydrogen Gas

April 26, 2019
Author(s)
Elizabeth S. Drexler, Andrew J. Slifka, Robert L. Amaro, Jeffrey W. Sowards, Matthew J. Connolly, May L. Martin, Damian S. Lauria
Several welds and associated heat-affected zones (HAZs) on two API X70 and two API X52 pipes were tested to determine the fatigue crack growth rate (FCGR) in pressurized hydrogen gas and assess the area of the pipe that was most susceptible to fatigue when

Hydrogen Isotope Effect in Embrittlement and Fatigue Crack Growth of Steel

March 7, 2019
Author(s)
Matthew J. Connolly, Andrew J. Slifka, Robert L. Amaro, Elizabeth S. Drexler, May L. Martin
The corrosive effect of hydrogen on steel is a long-standing problem. Corrosion in the presence of hydrogen is, in part, a consequence of the fast diffusion of hydrogen in ferritic steels. Because of the identical chemical properties but large differences

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

Fatigue measurement of pipeline steels for application of gaseous hydrogen transport

February 5, 2018
Author(s)
Andrew J. Slifka, Elizabeth S. Drexler, Robert L. Amaro, Louis E. Hayden, Damian S. Lauria, Nikolas W. Hrabe, Douglas G. Stalheim
A comprehensive testing program to determine the fatigue crack growth rate of pipeline steels in pressurized hydrogen gas was completed; the project was sponsored by the Department of Transportation, and was conducted in close collaboration with the ASME

FATIGUE CRACK GROWTH RATES OF API X70 PIPELINE STEELS IN PRESSURIZED HYDROGEN GAS COMPARED WITH AN X52 PIPELINE IN HYDROGEN SERVICE

September 1, 2017
Author(s)
Elizabeth S. Drexler, Andrew J. Slifka, Robert L. Amaro, Damian S. Lauria, Jeffrey W. Sowards
At the present time, steel selection for hydrogen pipelines is limited to API X52 grade. However, the code is being modified to include higher strength steels, such as X70. Fatigue crack growth (FCG) tests were conducted at NIST (Boulder) on an X52

APPLICATION OF A MODEL OF HYDROGEN-ASSISTED FATIGUE CRACK GROWTH IN 4130 STEEL

July 31, 2017
Author(s)
Andrew Slifka, Robert L. Amaro, Devin T. O'Connor, Benjamin E. Long, Elizabeth S. Drexler
In this work, we applied a finite element model to predict the cyclic lifetime of 4130 steel cylinders under the influence of hydrogen. This example is used to demonstrate the efficacy of a fatigue crack growth (FCG) model we have developed. The model was