Steels for Sustainable Development: Hydrogen & New Applications
Sponsored by: TMS Steels Committee
Program Organizers: Ian Zuazo, ArcelorMittal Global R&D - Industeel; Matthias Militzer, University of British Columbia; Jonah Klemm-Toole, Colorado School of Mines; Kester Clarke, Los Alamos National Laboratory
Wednesday 8:00 AM
October 12, 2022
Room: 406
Location: David L. Lawrence Convention Center
Session Chair: Ian Zuazo, ArcelorMittal Global R&D - Industeel; Jonah Klemm-Toole, Colorado School of Mines
8:00 AM Invited
Probing Hydrogen-assisted Phase Transformations in Austenitic Stainless Steels Using Synchrotron X-ray Diffraction: Samantha Lawrence1; Reeju Pokharel1; Bjørn Clausen1; Donald Brown1; John Carpenter1; Mary O'Brien1; Christopher San Marchi2; 1Los Alamos National Laboratory; 2Sandia National Laboratories
Microstructures and defect populations produced by additive manufacturing (AM) are distinct from wrought products and influence performance in hydrogen-containing environments. The present work builds upon studies of microstructure, mechanical properties, and fracture of AM stainless steels (SS) by utilizing high energy synchrotron x-ray diffraction to probe hydrogen-metal interactions. The objective is to highlight unique aspects of hydrogen-deformation interactions and microstructural evolution during tensile deformation and fatigue loading of 304L SS produced through conventional upset forging and laser powder-bed fusion AM, with and without internal hydrogen (H). Solute H lowers the onset strain for austenite decomposition to martensite in both microstructures. The total fraction of transformation product is larger when the microstructure is H-saturated. Importantly, in the non-charged condition, forged SS did not undergo martensite transformation, while AM SS transformed readily at moderate strains. The interplay between microstructure, loading condition, and hydrogen content on propensity for austenite decomposition will be explored.
8:30 AM Invited
Microstructural Engineering of High Mn Duplex Steel to Achieve Low-cost, High-performance Solutions for Hydrogen Storage and Delivery: Yuran Kong1; Allison Kosberg1; Pawan Kathayat1; Lawrence Cho1; Kip Findley1; John Speer1; 1Colorado School of Mines
The cost and reliability of hydrogen storage and delivery infrastructure represent primary obstacles to the broader use of hydrogen energy technologies. In particular, high Ni austenitic stainless steels have high resistance to hydrogen embrittlement but are relatively costly. To overcome this obstacle, the current study aims at designing Mn-alloyed duplex steels as economical alternatives to high Ni stainless steels for hydrogen service. The alloy design was guided by previously understood effects of alloying on austenite stacking fault energy, which is correlated with the mechanical stability of austenite and hydrogen embrittlement resistance. In the hot-rolled condition, the designed duplex steel showed superior hydrogen embrittlement resistance compared to the commercial 255 duplex stainless steel. The hydrogen embrittlement properties of the designed alloy were also evaluated in cold rolled and aged conditions. The microstructure-driven hydrogen distribution and deformation mechanisms in both the high Mn and stainless steels were characterized through fractographic analyses.
9:00 AM
Development of Evaluation Method of Low Alloy Steel in Hydron Environment Using Concurrent Cathodic Hydrogen Charging: Yoshihiro Nishihara1; Ayaka Nozaki1; Hiroshi Okano1; Shusaku Takagi1; 1JFE steel corporation
In order to reduce the construction cost of hydrogen infrastructure facilities, application of inexpensive materials such as low alloy steel is required. For the application of materials of which hydrogen embrittlement is a concern such as low alloy steels, acquisition of material data in high pressure hydrogen gas and proof of safety are necessary, but the conduct of the test in high pressure hydrogen gas requires a large cost. In this study, as a simple evaluation technique of mechanical properties in high pressure hydrogen gas, concurrent cathodic hydrogen charging method which carried out mechanical test while introducing hydrogen electrochemically into steel was examined. When the tensile test at low strain rate was carried out in a continuous cathode hydrogen charging environment, fracture displacement equivalent to the test in high-pressure hydrogen gas was obtained.
9:20 AM
Influence of C and N on Hydrogen Embrittlement in
17Cr-10Ni-6Mn Stable Austenitic Stainless Steel
: Yeonggeun Cho1; Hyung-Jun Cho1; Sung-Joon Kim1; 1Postech
17Cr-10Ni-6Mn stable austenitic stainless steels containing 0.2 wt.% of C or N were hydrogen charged and tensile tested to compare the effect of interstitial elements on hydrogen embrittlement (HE). Addition of C or N increased the tensile strength and decreased the HE susceptibility, and improvement of HE resistance was greater by C than by N. Improvement of strength and HE resistance by C or N addition are mainly attributed to expansion of austenite lattice and increase of activation energy for hydrogen desorption. N showed lower solid solution hardening and less degree of twinning than C, which resulted in lower tensile strength in N-added steel. Activation energy for hydrogen desorption was higher in C-added steels, indicating that C was more effective on decreasing the hydrogen diffusivity, which corresponds to smaller depth of hydrogen-affected zone. In addition, N promoted planar slip and accelerated localized deformation, which contributed to higher HE susceptibility.
9:40 AM
Mechanical Property Alterations through Hydrogen Trapping by Nanocarbide Dispersions in Steels: Bahrum Rocky1; Shrestha Rakish2; Chris Marchi2; Ryan Wilkerson3; Chris Weinberger4; Steve Daniweicz1; Gregory Thompson1; 1University of Alabama; 2Sandia National Laboratories (SNL); 3National Aeronautics and Space Administration (NASA); 4Colorado State University (CSU)
A subset of transition metal carbides is identified to trap hydrogen for mitigating hydrogen embrittlement (HE). Using a powder metallurgy process, these carbide nanoparticles are dispersed in 304L stainless steel powder matrices and consolidated by direct current sintering. Tensile test specimens were extracted from the consolidated billets and then subjected to hydrogen gas-phase precharging before testing. The consolidated 304L specimens (with no carbide dispersion) exhibited similar mechanical performance to a wrought 304L sheet in the pre-and post-H-precharged states. With the carbide dispersion additions, up to 1.0 wt.%, the strength increased but with a corresponding decrease in ductility. After hydrogen precharging, all samples exhibited a reduction in ductility from their non-charged state; however, the net ductility loss between the non-charged and H-precharged conditions was reduced with the carbide presence. This talk will address the potential trapping mechanism(s) and optimization strategies in carbide dispersion contents to reduce HE sensitivity in these materials.
10:00 AM Break
10:20 AM Invited
Low-density, Medium-Mn Steels for Lightweighting: Influence of Al content on Microstructure and Tensile Properties: Tomas Scuseria1; Kelcey Garza2; Dean Pierce3; Jerry Arnold2; Amy Clarke1; Kester Clarke1; 1Colorado School of Mines; 2Cleveland-Cliffs; 3Oak Ridge National Laboratory
Low-density steels are a candidate for increased energy savings and performance for Advanced High Strength Steel (AHSS). Al additions (5-7 wt%) to medium-Mn steels provide lightweighting through density reductions, while promoting duplex microstructures with excellent tensile properties. Concurrently, Al stabilizes ferrite at high temperatures, creating local chemical gradients and banded microstructures that are sensitive to processing, in addition to altering the austenite stability and work-hardening characteristics, such as TRIP, TWIP, or planar slip. This influence of Al must be deconvoluted to establish robust alloy design strategies. Fe-Mn-Al-C alloys were produced into sheets and characterized in the cold-rolled and intercritically annealed condition. Increasing Al additions were found to be detrimental to tensile properties at fixed Mn and C content, while increasing the Mn and C content to suppress high ferrite fractions improved specific strength. Additionally, cryogenic treatment and tempering was used to study martensite-containing microstructures for increased strength.
10:40 AM
Evaluation of Heavy Gauges 690 MPa-class Offshore Steel Racks Required in Modern Wind Turbine Installation Vessels
: David Quidort1; Anne Higelin1; Aurélien Chaize1; Sophie Perret1; Jean-Christophe Milek1; 1INDUSTEEL FRANCE
Jack-up racks for wind turbine tower installation vessels require stronger teeth to withstand the enhanced wear caused by the higher frequency of up and down operations compared to classical exploration O&G drilling rigs. That is why design of WTIV is upscaled up to 10'' thick racks instead of the standard 7” gauge used for drilling platforms. Offshore structural steel with a nominal yield strength of 690 MPa is the reference material of choice in this application. Maintaining the same material performance while increasing the section is not a simple task. The same or better mechanical properties shall be guaranteed for the whole thickness and the material characteristics in terms of processing and welding must be qualified. This paper will highlight the experimental characterization of 8 and 10'' thick base metal plates the industrially produced by Industeel technological production facility in France. The SAW weld metal properties will be presented too.
11:00 AM
Maximizing Scrap Recycling by Designing Cu Tolerant Steel Compositions: Henry Geerlings1; Lionel Promel1; Amy Clarke1; Kester Clarke1; Jonah Klemm-Toole1; Sridhar Seetharaman1; 1Colorado School of Mines
Residual elements from scrap steel recycling, most notably copper, are known to result in processing challenges such as hot cracking during thermomechanical processing. As the concentration of copper and other residuals in steel scrap streams increases, Electric Arc Furnace (EAF) scrap recycling heats commonly use pig iron to dilute residuals below current limits. Our work focuses on establishing residual element tolerant compositions and concomitant processing windows that can simultaneously mitigate issues from residuals during thermomechanical processing. Alloy chemistry, microstructure, and hot forging conditions are being analyzed to establish a hot cracking mitigation model. The effects of residuals on transformation behavior upon cooling from common hardening and joining processes is also of interest. We aim to increase residual element tolerance in secondary steels, yielding a more sustainable manufacturing pathway with a substantially smaller carbon footprint.
11:20 AM
Development of Ultra-high Strength TWIP Steel with Increased Corrosion Resistance: Pavel Podany1; Tomas Studecky1; Tomas Gregor1; 1COMTES FHT a.s.
This paper describe the process of development of steal with TWIP mechanism. The purpose of this research was to develop fully austenitic steel with twinning mechanism with increased corrosion resistance. This was done by means of alloying with chromium. The heats were cast in an experimental melting furnace and subjected to hot and cold rolling. After cold rolling, the appropriate recrystallization annealing temperature ensured optimal grain size of austenite grains. X-ray diffraction analysis proved fully austenitic microstructure in both cold rolled and hot rolled conditions. After recrystallization annealing, the sheets reached very good combination of high yield and tensile strength with an elongation of more than 40 %. Addition of chromium increased corrosion resistance of this steel that could be compared with corrosion resistant grades of ferritic steels.