Article
Nanoscience & Nanotechnology
Hyung-Jun Cho, Yeonggeun Cho, Gang Hee Gu, Hyoung Seop Kim, Sunghak Lee, Sung-Joon Kim
Summary: The effects of Cu as an element on the deformation mechanisms and tensile ductility of austenitic stainless steels (ASSs) were investigated by varying the tensile strain rate. The study found that Cu and strain rate have different effects on the elongation, and there is a competition between two mechanisms.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Christian Wagner, Alberto Ferrari, Jurgen Schreuer, Jean-Philippe Couzinie, Yuji Ikeda, Fritz Koermann, Gunther Eggeler, Easo P. George, Guillaume Laplanche
Summary: The physical properties of ten single-phase FCC CrxMn20Fe20Co20Ni40-x high-entropy alloys were investigated. The lattice parameters of the alloys were nearly independent of composition, while the solidus temperatures increased linearly with increasing Cr content. The alloys did not exhibit ferromagnetism in a certain temperature range, and the temperature dependencies of their coefficients of thermal expansion and elastic moduli were independent of composition. Ab initio simulations qualitatively reproduced the magnetic transitions and magnetostriction observed in the alloys. The plastic deformation of the alloys was found to occur initially by the glide of perfect dislocations on {111} planes. The stacking fault energy (SFE) was determined and found to decrease with increasing Cr content. However, the calculated intrinsic SFEs were lower than the experimental values. The ab initio simulations showed that atomic relaxations, finite temperatures, and magnetism strongly influenced the intrinsic SFE.
Article
Materials Science, Multidisciplinary
Hyung-Jun Cho, Sung-Ho Kim, Yeonggeun Cho, Sung-Joon Kim
Summary: The effects of Cu on the tensile properties and deformation mechanisms of austenitic stainless steel were investigated. Adding Cu slightly decreased the yield strength and negligibly affected the ultimate tensile strength, but significantly reduced the fracture elongation. The motion of dislocations was also altered by Cu, with high-Cu-containing alloys exhibiting planar slip and high density of dislocation walls.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Physical
X. W. Zhou, C. Nowak, R. S. Skelton, M. E. Foster, J. A. Ronevich, C. San Marchi, R. B. Sills
Summary: Hydrogen reduces the stacking fault energy of Fe-Ni-Cr austenitic stainless steels, leading to decreased ductility, fatigue, and fracture properties when exposed to hydrogen environments.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Nanoscience & Nanotechnology
S. Shyamal, M. Ghiasabadi Farahani, T. Allam, A. S. Hamada, C. Haase, J. Komi, P. C. Chakraborti, P. Sahu
Summary: In a medium Mn austenitic steel containing precipitates, twin nucleation is influenced by unfaulting dislocation reaction near the precipitates, while twinning is activated farther from the precipitates. The formation of twin nuclei involves the creation of stacking faults through classical dislocation dissociation, followed by overlapping of these stacking faults through a non-classical mechanism to form a three-layer twin nucleus.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Hyung-Jun Cho, Yeonggeun Cho, Hojun Gwon, Sunghak Lee, Seok Su Sohn, Sung-Joon Kim
Summary: The effects of Ni/Cu replacement and subsequent aging treatment on the tensile and hydrogen embrittlement properties of Fe-Cr-Ni austenitic stainless steels were investigated. The results showed that the replacement enhanced tensile strength and ductility in the aged state, but reduced these properties in the as-annealed state. The formation of Cu-rich precipitates effectively interfered with hydrogen diffusion and increased the resistance to hydrogen embrittlement. However, excessive formation of Cu-rich precipitates destabilized the austenite phase and induced martensitic transformation, leading to earlier brittle fracture and severe hydrogen embrittlement.
Article
Nanoscience & Nanotechnology
Guanghui Chen, Guang Xu, Horst Biermann, Javad Mola
Summary: The effects of Co and Co + Al addition on the microstructure, deformation-induced processes, and mechanical properties of a wrought Fe-14Cr-9Ni-3Mn-0.3C austenitic stainless steel were investigated. Co and Co + Al additions have noticeable impacts on the mechanical properties, particularly on the work hardening rate and the suppression of α'-martensite.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Hamidreza Kamali, Haibo Xie, Fanghui Jia, Hongyun Bi, E. Chang, Haigang Xu, Haifeng Yu, Zhengyi Jiang
Summary: The microstructure and texture evolution of a low-Ni Cr-Mn-N austenitic stainless steel during a three-point bending process were analyzed, revealing differences in deformation-induced martensite fraction and texture between different regions.ε-Martensite and α'-martensite were observed in varying proportions between the two regions, leading to changes in texture and twin boundaries.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Wenting Lv, Luchun Yan, Xiaolu Pang, Lijie Qiao, Yanjing Su, Ilaria Salvatori, Kewei Gao, Huisheng Yang
Summary: The synergistic effect of Cu and Cr on pitting initiation in low alloy steels was investigated through experimental and computational methods, revealing that the stimulating effect of Cu on Cr is stronger, intensifying pitting corrosion in the steel.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Mechanical
Le Li, Zhenghao Chen, Koretaka Yuge, Kyosuke Kishida, Haruyuki Inui, Martin Heilmaier, Easo P. George
Summary: The plastic deformation behavior of equiatomic Cr-Fe-Co-Ni medium-entropy alloy was investigated through compression and tension experiments. The critical resolved shear stress (CRSS) for {111}<1((1)over bar)0> slip was found to be 44-45 MPa at room temperature without significant tension-compression asymmetry. The CRSS increased rapidly with decreasing temperature, but the temperature dependence dulled below 77 K due to the inertia effect. The 0 K CRSS was determined to be 200 MPa, higher than Cr-Mn-Fe-Co-Ni high-entropy alloy but lower than Cr-Co-Ni medium-entropy alloy.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Jaime A. Castaneda, Oscar A. Zambrano, German A. Alcazar, Sara A. Rodriguez, John J. Coronado
Summary: A critical assessment was conducted to determine the stacking fault energy (SFE) of the austenite phase in high manganese steels using X-ray diffraction (XRD), revealing a substantial variation in SFE with chosen elastic constants, leading to potential errors of up to 37%. The study aimed to establish a more direct and reliable methodology for calculating SFE by XRD, and found that uncertainty in elastic constants can significantly impact the estimated values.
Article
Metallurgy & Metallurgical Engineering
Wen-Long Jin, Jin-Li Cao, Jin-Xu Li
Summary: In this study, the combined effects of manganese, carbon, and hydrogen on the stacking fault energy (SFE) in austenitic Fe1-xMnx alloys were investigated using first-principles calculations. It was found that the influence of carbon and manganese on SFE varies in different alloys, with the unique manganese-carbon effect attributed to the formation of trimers. Additionally, the enhancing effect of hydrogen weakens with increasing manganese content, and the ternary Mn-C-H effect is generally stronger than binary effects.
STEEL RESEARCH INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Trishelle M. Copeland-Johnson, Charles K. A. Nyamekye, Lynne Ecker, Nicola Bowler, Emily A. Smith, Raul B. Rebak, Simerjeet K. Gill
Summary: In this investigation, multi-modal characterization was used to evaluate the oxidation of Stainless Steel 304 under laboratory air and 100% steam (1200 degrees C, 2 h). Air oxidation resulted in Fe(NiMn)O4, Fe3O4, Fe(3,0CrxO4, and Cr2O3. Steam oxidation produced a dual layer structure, with a porous outer layer enriched in Fe2O3 and a sub-surface matrix of Fe3O4/Fe(3,0CrxO4 with SiO2/Fe(3_ x)SixO4. Based on these findings, an oxidation mechanism was proposed. The arrangement of oxidation products in air aligned with anticipated diffusion behavior, except for Cr2O3. However, the arrangement in steam deviated due to intergranular interactions with H2O, resulting in the formation of the sub-surface matrix.
Article
Metallurgy & Metallurgical Engineering
Michael Hauser, Olena Volkova, Marco Wendler
Summary: The mechanical properties of two metastable austenitic cast steels were examined through tensile tests in a temperature range of -70 to 300°C. The M-s and M-d temperatures for the 16-6-6 steel were -30°C and 100°C, respectively. The possibility of athermal martensite formation below -196°C was excluded for the X3CrNiCuN17-6-4 steel. The M-d temperature for X3CrNiCuN17-6-4 steel was found to be 130°C. The results obtained from a semiempirical thermodynamic-mechanical calculation model were compared to experimental results from tensile tests.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Nanoscience & Nanotechnology
Yun-Fei Du, Hui-Hu Lu, Xing-Quan Shen
Summary: This research investigated the effects of austenitizing temperature on microstructure evolution and mechanical performance of banded structured Cr-Ni-Mo-V steel. The results show that increasing austenitizing temperature improves the tensile strength, ductility, and toughness of the steel simultaneously. Delaminated cracks are mainly found at the interface between fine-grained and coarse-grained areas, where the blunting of crack tip and transformation of stress state are suggested to be responsible for the improvement of ductility and toughness.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Metallurgy & Metallurgical Engineering
Pablo Miguel Coha-Vesga, Martin Emilio Mendoza-Oliveros, Fabio Raul Perez-Villamil, Francisco Gil Coury, Lais Mujica-Roncery
Summary: Nitrogen-containing steels with excellent mechanical properties have gained popularity in industrial fields. This study successfully produced carbon-nitrogen martensitic steels at low pressure and analyzed their composition, thermodynamics, heat treatment, and mechanical properties.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Johannes Boes, Arne Roettger, Christian Mutke, Christoph Escher, Sebastian Weber
Summary: Laser additive manufacturing techniques allow for the production of complex-shaped parts. The cold crack susceptibility of carbon-martensitic tool steels limits their processability, but substrate preheating can mitigate this issue. However, preheating may have disadvantages for part quality and powder reusability. This study investigates a carbon-martensitic steel that can be manufactured without preheating to produce parts with low crack densities.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Isabel Hahn, Sabine Siebert, Rainer Fluch, Werner Theisen, Sebastian Weber
Summary: The development of NbC-containing martensitic stainless steels has allowed for the combination of high corrosion resistance and wear resistance. By using NbC instead of chromium carbide as the hard phase, the steels exhibit increased abrasive wear resistance due to the greater hardness of NbC. The low solubility of chromium in NbC allows for the formation of a passive surface layer that enhances corrosion resistance. Current production methods for steels with NbC as the hard phase involve complex and expensive diffusion alloying processes. However, this study presents a novel Nb-rich MC-containing steel that is produced using the usual powder metallurgy route. This steel demonstrates outstanding tribocorrosion resistance in a 0.9% NaCl solution, attributed to its high hardness (>750 HV30) and resistance to pitting corrosion.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Engineering, Mechanical
P. K. Farayibi, J. Hankel, F. van Gen Hassend, M. Bluem, S. Weber, A. Roettger
Summary: This study investigates the scratch resistance of a heat-treated stainless steel densified under vacuum and a nitrogen atmosphere. It is found that the nitrogen-sintered steel sample, deep cryogenically treated, exhibits better scratch resistance due to effective load transfer between the hard phases and the matrix.
Article
Green & Sustainable Science & Technology
Felix Grosswendt, Vincent Buerk, Bryan Kopanka, Sebastian Jaeger, Stefan Pollak, Lennart Leich, Arne Roettger, Marcus Petermann, Sebastian Weber
Summary: This study examines the possibility of reusing AISI D2 tool steel grinding sludge as a secondary raw material in a powder metallurgical process. The grinding sludge initially contains silicon carbide and aluminium oxide abrasive particles, as well as a cooling lubricant emulsion. A three-stage decontamination procedure is performed to remove non-metallic abrasive particles and recover the cooling lubricant oil. The prepared grinding metal chips are densified using electric discharge sintering. However, the recycled material shows different alloying composition and lower compressive strength compared to the cast reference material, due to remaining contaminations and inadequate removal of oxidic abrasive particles during the recycling process.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Materials Science, Multidisciplinary
Inmaculada Lopez-Galilea, Lisa Hecker, Alexander Epishin, David Buerger, Benjamin Ruttert, Pascal Thome, Sebastian Weber, Werner Theisen
Summary: Super-solidus hot isostatic pressing (SSHIP) heat treatment, developed for the first time and applied to the third-generation Ni-base single crystal superalloy CMSX-10 K, aims to reduce the total time required for solution heat treatment and enhance mechanical properties compared to conventional routes. SSHIP is an innovative, economical, and sustainable approach applicable to all types of Ni-base SX superalloys, particularly those with high refractory element content and a large volume fraction of eutectic microstructure in the as-cast state.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Aaron Berger, Gero Egels, Robert Fussik, Santiago Manuel Benito, Sebastian Weber
Summary: In this study, a novel approach combining automated solidification simulations and multi-objective optimization algorithm is developed to optimize alloy compositions and improve the homogeneity of austenite stability. The approach has been exemplarily applied to the compositional range of 1.4307/AISI 304L, showing a significant increase in austenite stability homogeneity.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Metallurgy & Metallurgical Engineering
Diego Fernando Avendano-Rodriguez, Rodolfo Rodriguez-Baracaldo, Sebastian Weber, Lais Mujica-Roncery
Summary: The research focuses on analyzing the damage evolution and microstructural fracture mechanisms of dual-phase steels under quasi-static uniaxial and cyclic tensile tests, considering the influence of martensite volume fraction and distribution. Intercritically annealed samples at different temperatures are used to obtain varying martensite volume fractions. Damage evolution is evaluated based on stiffness loss, revealing lower ductility and strength under cyclic loading conditions. The presence of higher martensite volume fractions results in a faster rate of damage evolution. The primary void nucleation mechanisms observed are ferrite-martensite and ferrite-ferrite decohesion, while martensite fracture is activated based on martensite volume fraction and distribution along the ferrite grain boundary. The high dislocation density on grain boundaries is attributed to the austenite-martensite transformation during quenching and subsequent plastic deformations, and is related to stored strain energy, stress concentration, and fracture mechanisms near martensite grains. Nanoindentation is conducted to evaluate the hardness of ferrite and martensite, which is influenced by their carbon content. The martensite/ferrite hardness ratio is found to affect the uniform elongation of the material.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Felix Stern, Louis Becker, Jochen Tenkamp, Johannes Boes, Jonathan Lentz, Sebastian Weber, Frank Walther
Summary: The impact of nitrogen alloying on corrosion and corrosion fatigue behavior of austenitic stainless steel AISI 316L processed via laser beam powder bed fusion (PBF-LB) was investigated. The nitrogen alloyed steel showed improved pitting corrosion and fatigue behavior. A fracture mechanical approach was used to analyze the fatigue data and identify the improved defect tolerance due to nitrogen alloying.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Industrial
L. Becker, J. Lentz, S. Benito, C. Cui, N. Ellendt, R. Fechte-Heinen, S. Weber
Summary: This paper compares the microstructure formation mechanisms during laser powder bed fusion (PBF-LB/M) processing of in-situ alloyed powder mixture (PM) and pre-alloyed (PA) powder. The microstructures of PM and PA differ significantly in terms of ferritic and austenitic phase fractions. The increased chemical inhomogeneities of PM compared to PA result in the formation of a finer microstructure and higher hardness for PBF-LB/M-built PM.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
G. Egels, M. Bussmann, S. Weber, S. Weber
Summary: This study investigates the deformation-induced alpha-martensite formation in AISI 304L steel at different temperatures. Experimental results show that reducing the temperature to -75 degrees C increases the alpha-martensite volume content and shifts the phase transformation to lower strain levels. Further reducing the temperature to -196 degrees C has no significant impact on the alpha-martensite formation. Theoretical assessments suggest that thermal friction work contributes to the constant austenite stability in low-temperature regimes.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Construction & Building Technology
Lukas Brackmann, Arne Roettger, Michelle Treppmann, Sebastian Weber
Summary: In the case of a heterogenous ground condition, tunneling tools are exposed to cyclic loading that may exceed their permanent load-bearing capacity, causing fatigue crack growth and material spalling. The underlying micromechanism and counteraction of fatigue on tunneling tools still require further research.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Monica Keszler, Felix Grosswendt, Anna-Caroline Assmann, Martin Krengel, Fernando Maccari, Oliver Gutfleisch, Doris Sebold, Olivier Guillon, Sebastian Weber, Martin Bram
Summary: Recycling of Nd-Fe-B magnets is a challenge, but combining FAST/SPS and flash SPS techniques can directly produce magnets from 100% scrap material with properties similar to commercial magnets.
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2023)
Article
Chemistry, Physical
Jose Y. Aguilar-Hurtado, Alejandro Vargas-Uscategui, Laura Gabriela Torres-Mejia, Lais Mujica-Roncery, Dario Zambrano-Mera, Stefano Pantaleone, Bo Wang, Andreas Rosenkranz, Katherine Paredes-Gil
Summary: The effect of boron doping on the stacking fault energy of Fe50_XMn30Co10Cr10BX multi-component alloys was experimentally and computationally assessed. It was found that increasing boron content resulted in higher stacking fault energy, leading to changes in deformation mechanisms and martensitic transformation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
