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Article
Open AccessUltrastrong and ductile steel welds achieved by fine interlocking microstructures with film-like retained austenite
The degradation of mechanical properties caused by grain coarsening or the formation of brittle phases during welding reduces the longevity of products. Here, we report advances in the weld quality of ultra-hi...
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Article
Hydrogen Trap** Characteristics and Mechanical Degradation in a Duplex Stainless Steel
We investigated the hydrogen behaviors and corresponding mechanical degradation in the duplex stainless steel under the ex-situ and in-situ cathodic charging condition. In the ex-situ condition, where the hydr...
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Article
Heat-Affected Zone Characteristics with Post-Weld Heat Treatments in Austenitic Fe–Mn–Al–C Lightweight Steels
This study investigates the relationship between the mechanical characteristics and microstructural transitions in heat-affected zone (HAZ) of various austenitic Fe–Mn–Al–C lightweight steels. The analysis was...
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Article
Correlation Between Constituent Phase and Weld Metal Properties in Ni-Reduced Duplex Stainless Steel
The intrinsic properties of austenite and ferrite on the mechanical properties and corrosion resistance of the duplex stainless steel weld metals was studied by substituting Ni with Mn, N, and Mn + N. The prop...
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Article
Microstructure and High-Temperature Strength in the Weld Coarse-Grained Heat-Affected Zone of Fire-Resistant Steels and the Effects of Mo and Nb Additions
The microstructural evolution and fire-resistant properties in the weld heat-affected zone (HAZ) of Mo and Mo + Nb-added fire-resistant steels were investigated. For this purpose, three Fe-0.1 wt%C-1.5 wt%Mn-0...
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Article
On the Strengthening Effects Affecting Tensile and Low Cycle Fatigue Properties of Low-Alloyed Seismic/Fire-Resistant Structural Steels
In the present study, low carbon ferritic and bainitic steels with different contents of Mo, Ti, and Nb were designed for both seismic and fire-resistant applications. The microstructure of steels containing 0...
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Article
Open AccessStrain hardening recovery mediated by coherent precipitates in lightweight steel
We investigated the effect of κ-carbide precipitates on the strain hardening behavior of aged Fe–Mn-Al-C alloys by microstructure analysis. The κ-carbides-strengthened Fe–Mn-Al-C alloys exhibited a superior st...
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Article
Hydrogen Behavior in Ti-Added Reduced Activation Ferritic-Martensitic Steels
Hydrogen behavior and corresponding mechanical degradation were examined in TaTi-RAFM and EUROFER97 steels. Increased Ta content with Ti addition decelerates the hydrogen diffusion but increases the solubility...
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Article
Open AccessA new class of lightweight, stainless steels with ultra-high strength and large ductility
Steel is the global backbone material of industrialized societies, with more than 1.8 billion tons produced per year. However, steel-containing structures decay due to corrosion, destroying annually 3.4% (2.5 ...
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Article
Synergistic Effect of He and H on the Surface Swelling of Ion-implanted Ti/Ta-added Reduced Activation Ferritic/Martensitic Steel for Fusion Reactors
Surface swelling caused by He implantation was studied for newly-developed Ti/Ta-added reduced-activation ferritic/martensitic (RAFM) steels. Post-implantation annealing at 623 K for 2 h of He-implanted RAFM-s...
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Article
Hot Deformation Characteristics of 9Cr-1.5Mo-1.25Co-VNb Ferritic-Martensitic Steel
The hot workability of 9Cr-1.5Mo-1.25Co-VNb ferritic-martensitic steel was investigated through hot compression tests using Gleeble simulator over a temperature range of 1223 K (950 °C) to 1573 K (1300 °C) and...
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Article
Open AccessDirect observation of dislocation plasticity in high-Mn lightweight steel by in-situ TEM
To gain the fundamental understanding of deformation mechanisms in an aluminum-containing austenitic high-Mn steel (Fe-32Mn-8.9Al-0.78 C (wt.%)), in-situ straining transmission electron microscopy (TEM) analysis ...
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Article
The Effect of the Hyperstoichiometric Ti/N Ratio Due to Excessive Ti on the Toughness of N-Controlled Novel Fire- and Seismic-Resistant Steels
The toughness of the base material (BM) and the coarse-grain heat-affected zone (CGHAZ) of N-controlled fire- and seismic-resistant (FSR) steels (FSR1: 0.03Ti, 0.25Mo, 0.018Nb; FSR2: 0.07Ti, 0.09Mo; and FSR3: ...
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Article
Roles of (Fe, Mn)3Al Precipitates and MBIP on the Hot Ductility Behavior of Fe–30Mn–9Al–0.9C Lightweight Steels
In the automotive industry, lightweight steel has received much attention because steel comprises a significant portion of a vehicle’s total weight. Fe–Mn–Al–C steel is a representative lightweight steel due t...
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Article
Effect of Mn and C on Age Hardening of Fe–Mn–Al–C Lightweight Steels
The effects of Mn and C content on the age hardening of Fe–Mn–Al–C lightweight steels, which have austenitic or duplex (austenite and ferrite) microstructures, were investigated. An increase in Mn content indu...
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Article
Microstructure Evolution and Age-Hardening Behavior of Microalloyed Austenitic Fe-30Mn-9Al-0.9C Light-Weight Steels
The aging behavior and mechanical properties of microalloyed austenitic Fe-30Mn-9Al-0.9C light-weight steels were investigated through transmission electron microscopy analysis, electron backscatter diffractio...
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Article
Hot Ductility Behaviors in the Weld Heat-Affected Zone of Nitrogen-Alloyed Fe-18Cr-10Mn Austenitic Stainless Steels
Hot ductility behaviors in the weld heat-affected zone (HAZ) of nitrogen-alloyed Fe-18Cr-10Mn austenitic stainless steels with different nitrogen contents were evaluated through hot tension tests using Gleeble...
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Article
Effect of Heat Input on Microstructure Evolution and Mechanical Properties in the Weld Heat-Affected Zone of 9Cr-2W-VTa Reduced Activation Ferritic-Martensitic Steel for Fusion Reactor
The phase transformation and mechanical properties in the weld heat-affected zone (HAZ) of a reduced activation ferritic/martensitic steel were explored. The samples for HAZs were prepared using a Gleeble simu...
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Article
Effect of Nitrogen Partitioning on Yield Strength in Nitrogen-Alloyed Duplex Stainless Steel During Annealing
Nitrogen partitioning and its effect on the yield strength in nitrogen-alloyed duplex stainless steel during annealing were investigated at different annealing temperatures. The decrease in the austenite fract...
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Article
Tensile Deformation Behavior and Phase Transformation in the Weld Coarse-Grained Heat-Affected Zone of Metastable High-Nitrogen Fe-18Cr-10Mn-N Stainless Steel
The tensile deformation behavior and phase transformation in the weld coarse-grained heat-affected zone (CGHAZ) of a metastable high-nitrogen austenitic stainless steel was explored through tensile tests, nano...
