Fe Cr Mn Research Articles

Magnetization processes features in the tapes of cobalt-based amorphous alloy

Studies of the amorphous cobalt-based soft magnetic alloy AMAG-172 (Co–Ni–Fe–Cr–Mn–Si–B) from different manufacturers have shown that in the as-quenched state there is nonuniformity of the magnetic characteristics, and therefore the level of internal stresses across the width of the tape produced by MSTATOR (Borovichi) significantly lower. However, similar to the tape produced by NIIMET (Kaluga), there is nonuniformity of the tape in thickness, which contributes to the formation of a bimodal field dependence of magnetic permeability.This may be a consequence of the non-uniform concentration along the width of the tape of hydrogen and oxygen atoms embedded in its surface during interaction with atmospheric vapor and the presence of temperature gradients during the manufacturing process. A stepwise shape of the initial sections of the magnetization curves in the region of the first maximum of magnetic permeability was discovered. The abrupt nature of the magnetization processes in the region of weak fields allows us to conclude that in the samples of tape produced by MSTATOR, the formation of the first maximum of the field dependence is associated with an independent magnetization reversal of the surface layer, while the main layer of the tape participates in the formation of the second maximum. The smoothed shape of the stepped initial section of the magnetization curve of samples produced by NIIMET corresponds to the gradual involvement of the main layer of the tape in the processes of magnetization and remagnetization. A comparison of the hysteresis loops of both parts of the tape, measured in the same magnetic field region, shows that the field shift of the hysteresis loops is associated with the interlayer interaction of the surface and volume of the tape, and the formation of asymmetric hysteresis loops occurs with the participation of the second layer with its gradual involvement in the processes of magnetization and magnetization reversal.

Structural Change in Co–Cr–Fe–Mn–Ni Alloys upon Variation in Mn and Fe Concentrations

Structural Change in Co–Cr–Fe–Mn–Ni Alloys upon Variation in Mn and Fe Concentrations

Study of engineering developing decagonal-like rational approximant structure of Al–Ni–Cu–Fe–Mn–Cr senary system in aluminum alloy through additive manufacturing

Quasi-periodic materials hold unique properties, but mass-producing bulk materials with such structures remains challenging. The rational approximant phase belongs to the Bravais crystal system but exhibits irrational cut features and diffraction symmetries, which are similar to quasicrystals. This study uses additive manufacturing (AM) and prolonged annealing to create an aluminum-based alloy featuring a quasicrystal-like rational approximant phase, Al6(Cu, Ni)1(Cr, Mn, Fe)1, overcoming the production limitations of reproducible quasi-periodic materials. This phase transformation occurs at the Al–Al9FeNi interface, resulting in a monoclinic periodic structure with long-range translational symmetry. The structure comprises sublattices of stars and compressed hexagons, forming tile mode coverings with pseudo-five-fold decagonal shield-like tiles (SLTs) through transition-element atoms. Furthermore, HAADF imaging reveals clear dark monoclinic rhombic patterns with long-range ordered translational symmetry, free from atomic defects. The rational approximant phase has been verified crystallography through X-ray diffraction, confirming its translational symmetry. Additionally, the Al3(Zr, Sc) phase facilitates the phase transformation process through lattice interactions. These findings introduce a novel perspective on the phase transformation in decagonal-like rational approximants and broaden the realm for future engineering applications.

Effects of the Cr and Ni Concentrations on the Fatigue and Corrosion Resistances of Fe–Mn–Cr–Ni–Si Alloys for Seismic Damping Applications

Effects of the Cr and Ni Concentrations on the Fatigue and Corrosion Resistances of Fe–Mn–Cr–Ni–Si Alloys for Seismic Damping Applications

The Microstructure Refinement and Mechanical Properties Improving of Friction Stir Processed Fe–Mn–Cr–N Steel

The Microstructure Refinement and Mechanical Properties Improving of Friction Stir Processed Fe–Mn–Cr–N Steel

Influence of Ni additions on microstructure, non-magnetic properties, and wear resistance of Fe–Mn-Cr alloy deposited by metal-cored arc welding

Influence of Ni additions on microstructure, non-magnetic properties, and wear resistance of Fe–Mn-Cr alloy deposited by metal-cored arc welding

On the Methodology of the Quantitative Analysis of Fe–Cr–Mn–Mo–N–C Steels Reinforced with Oxide and Nitride Particles Using an Energy Dispersive X-Ray Fluorescence Spectrometer BRA-135F

On the Methodology of the Quantitative Analysis of Fe–Cr–Mn–Mo–N–C Steels Reinforced with Oxide and Nitride Particles Using an Energy Dispersive X-Ray Fluorescence Spectrometer BRA-135F

Thermodynamic database for multi-principal element alloys within the system Al–Co–Cr–Fe–Mn–Ni–C

The development of multi-principal element alloys requires the navigation within a multi-dimensional composition space, which has proven to be challenging. Various methods to predict the state of an alloy, in particular if it is single-phase or not, have been tested with various success. The only approach that can consistently predict the constitution of an alloy, e.g. single-phase, multi-phase, intermetallics, is thermodynamic calculations using Calphad databases. Conventional Calphad databases, such as steel or Ni-base, are of limited use since they are developed for alloys with a specific base element. More suitable databases, such as TCHEA, have been developed, but their development is challenging since they require the inclusion of more subsystems than conventional databases. The predictive capability depends strongly on which elements are considered, and their development is still ongoing. A Calphad database including the elements Al, Co, Cr, Fe, Mn, Ni and C was built up from scratch using mostly assessments of binary and ternary systems from the literature, but with many amendments. This database covers a substantial fraction of the alloys investigated until now plus the element C that is usually not included, but can provide additional strengthening, either in solution or in the form of carbides.

The deterministic effect of laser energy density on the microstructures of novel duplex stainless steel fabricated via in-situ alloying in laser powder bed fusion

Distinctive microstructures and distributions of novel duplex (ferrite δ + austenite γ) stainless steel can be fabricated using in-situ alloying of Fe–Cr–Mn alloy and pure Ni powders by tuning laser energy density in powder bed fusion. At low-level energy density (∼60 J/mm3), ferrite solidification dominates and results in bimodal ferrite of columnar and equiaxed grains. At medium energy density (∼100 J/mm3), fine acicular Widmanstätten austenite satisfying the Nishiyama-Wassermann orientation relationship was produced within the coarse grains of δ, which is the predominant phase although ferrite and austenite solidification occur. At high-level energy density (∼194 J/mm3), ferrite and austenite solidification occur and the resultant microstructure consists of nearly equivalent fine equiaxed-grained δ and γ. The key difference in the microstructure was attributed to the different melt pool overlapping and types, which can be characterized by the size and local ratio of Cr equivalent (Creq) and Ni equivalent (Nieq) values (Creq/Nieq). The melt pool characteristics fundamentally determine the local solidification and transformation mode at different energy densities. The testing results have shown that the novel duplex stainless steel possesses excellent mechanical properties compared to conventionally-manufactured counterparts.

Effect of Mn Content on Microstructure and Mechanical Properties of Fe–Mn–Cr–C High‐Manganese Steels Produced Using Laser‐Directed Energy Deposition

The microstructure and mechanical properties of high‐manganese steel (HMnS) fabricated using laser‐directed energy deposition (LDED) with Fe–Mn–4Cr–0.4C alloys with Mn contents of 13, 18.5, and 24 wt% are investigated. Additionally, the effect of annealing heat treatment on the microstructure and mechanical properties of the deposited HMnS is examined. Regardless of the manganese content, the deposited HMnS exhibits a fine microstructure without any defects (cracks or voids) and a strong fibrous texture along the <001>//building direction of the primary austenite phase. In addition, regardless of the manganese content, the grain size increases during annealing heat treatment, and the hardness decreases as the annealing temperature increases. The strength tends to decrease as the Mn content increases in the as‐built state. In addition, regardless of the Mn content, the yield strength and ultimate tensile strength tend to decrease owing to the effect of annealing heat treatment. Although the maximum elongation of 18.5Mn and 24Mn does not change significantly upon heat treatment, the maximum elongation of 13Mn is greatly reduced by annealing. The deformation behavior of HMnS is characterized by transformation‐induced plasticity (TRIP) for 13Mn and both TRIP and twinning‐induced plasticity for 18.5Mn and 24Mn.

Structural-Phase Composition and Hardness of Steel of the Fe–Cr–Mn–Mo–Al–Mg–N–C System Obtained by the Method of Self-Propagating High-Temperature Synthesis Under Nitrogen Pressure

Structural-Phase Composition and Hardness of Steel of the Fe–Cr–Mn–Mo–Al–Mg–N–C System Obtained by the Method of Self-Propagating High-Temperature Synthesis Under Nitrogen Pressure

High‐Temperature Oxidation Behavior of Medium‐Manganese Austenitic Steel

The high‐temperature oxidation behavior of medium‐manganese austenitic steel is investigated. The double‐layered oxide scale is formed in the investigated samples. The outer oxide layer consists of (Fe,Mn)‐rich oxides, while the inner oxide layer is mainly composed of AB2O4 spinel oxides. When the oxidation temperature is 800 °C, a region composed of oxide and ferrite is formed in the substrate surface layer. When the oxidation temperature is 900 and 1000 °C, there is no such region observed in the substrate surface layer. Although the content of Al in the Fe–Mn–Al sample and the content of Si in the Fe–Mn–Si sample are relatively lower than the content of Cr in the Fe–Mn–Cr sample, the oxidation resistance of the Fe–Mn–Al and Fe–Mn–Si samples is still better than that of the Fe–Mn–Cr sample. The oxidation resistance of the Fe–Mn–Cr–Al and Fe–Mn–Cr–Si samples is also better than that of the Fe–Mn–Cr sample. The addition of Al and Si can improve the oxidation resistance of the Fe–Mn–Cr sample. Besides, the oxidation resistance improvement effect of adding Si to the Fe–Mn–Cr sample is better than that of adding Al to the Fe–Mn–Cr sample.

Atomic Scale Diffusion Study in Quaternary and Quinary Alloys of Co–Cr–Fe–Mn–Ni System

Atomic Scale Diffusion Study in Quaternary and Quinary Alloys of Co–Cr–Fe–Mn–Ni System

Predicting the stacking fault energy in FCC high-entropy alloys based on data-driven machine learning

The properties of high-entropy alloys (HEAs) depend primarily on the composition and content of elements. However, getting the optimal composition of alloying elements through the traditional "trial and error" method is challenging, especially for non-equiatomic HEAs with a wide range of composition space. In this study, based on the knowledge that stacking fault energy (SFE) is the most crucial intrinsic property to determine the deformation mechanism and to optimize the mechanical properties of FCC HEAs, classical machine learning classification models including support vector classification (SVC) and random forest (RF), and deep learning regression model (Back Propagation Neural Network) were established to predict the stacking fault energy of Co–Cr–Fe–Mn–Ni–V–Al high-entropy alloys. These models can obtain the SFE data of any atomic ratio composition of the FCC structured Co–Cr–Fe–Mn–Ni–V–Al high-entropy alloy quickly and accurately. The high accuracy of these models indicates that using the compositions as features to predict stacking fault energy is feasible. Meanwhile, the monotonic relationship between alloying elements and SFE makes it possible to change the SFE of high-entropy alloy by fine-tuning the composition to realize the control of material deformation mechanism and mechanical properties. Component-based machine learning models provide a new method for rapidly discovering high-entropy alloys with exceptional strength and flexibility.

Особливості структуроутворення в економнолегованих хромомарганцевих залізовуглецевих сплавах для гірничо-металургійного обладнання

It was established that in cast chromium-manganese alloys of the transition class Fe–C–Mn–Cr system (carbon content no more than 2.2%) with a certain combination of Mn and Cr, the formation of crystals of highly hard carbide Me7C3 is possible. The relationship between the phase-concentration parameters and the structure formation of alloys of the Fe–C–Mn–Cr system was studied, the analysis of the relationship between the phase-concentration parameters, structure formation and properties was carried out on the compositions of the Fe–C–Mn and Fe–C– Mn–Cr with 1.5-2.1% C, with a variable content of Mn, Cr and additives of other alloying elements - Si and Ni at the level of impurities. A phase-concentration diagram of the crystallization of the alloys of this system was constructed, delimiting the regions of crystallization P → γ-Fe, P → γ-Fe + Me3C and P →(γ -Fe + Me7C3) + (γ-Fe + Me3C). It is shown that economically alloyed chromium-manganese alloys of the Fe–Mn–Cr–C system with eutectics based on Me7C3 carbide are characterized by a high level of shock-abrasive wear resistance, and the results of the conducted studies indicate the prospects of using economically alloyed chromium-manganese alloys and can be recommended for further research and use as wear-resistant materials for the manufacture of parts of replaceable metallurgical equipment, which are operated in severe conditions of abrasive and shock-abrasive wear. Keywords: phase-concentration diagram, microstructure, Me7C3 carbide, impact-abrasive wear resistance, chromium-manganese alloys

Composition stability of single fcc phase in Cr–Fe–Mn–Ni alloys: First-principles prediction and experimental validation

The relative phase stability of fcc and bcc Cr–Fe–Mn–Ni alloys has been investigated using a combination of density functional theory, cluster expansion (CE), and Monte Carlo (MC) simulations. The MC simulations for fcc and bcc Cr–Fe–Mn–Ni alloys performed using the CE models enabled computing the Gibbs free energies of formation of 1767 fcc and bcc alloys in the whole range of compositions of each element and analyzed as a function of temperature. In order to determine regions of stability of single fcc/bcc structures and atomic fractions of these phases in two-phase regions, we constructed the thermodynamic databases (TDBs) derived from MC simulations with their application in the OpenCalphad calculations. The results obtained using this approach are in qualitative agreement with the available experimental data from the literature and the experiments performed within this work for the samples of [CrFeMn]100−xNix (x = 20, 25 and 35 at.%) alloys synthesized using arc-melting and annealed at 1273 K for 48 h. The analysis of fcc fractions of the near-equiatomic alloy compositions has enabled the identification of the alloys that are predicted to be single fcc phase for a wide range of temperatures.

Effect of a High Temperature Brazing Thermal Cycle on the Microstructure and Mechanical Properties of Fe–Cr–Mn–Ni–C Stainless Steel

Effect of a High Temperature Brazing Thermal Cycle on the Microstructure and Mechanical Properties of Fe–Cr–Mn–Ni–C Stainless Steel

Synthesis and Characterization of Innovative Fe–Cr–Mn Ferritic Stainless Steel by Laser Powder Bed Fusion

Crack development for laser‐fused metallic materials is one major challenge for laser‐based powder bed fusion (LPBF). The cracks are manifested in two forms, i.e., macrocracks along building layers due to spalling and microcracks along the high‐angle grain boundaries. To mitigate the crack formation, a new type of ferritic stainless steel Fe–Cr–Mn are synthesized by LPBF. The well‐developed columnar ferrite grains with an enhanced fine acicular austenite precipitation, which possess Nishiyama–Wassermann (N–W) orientation relationship with the ferrite matrix, can be readily produced when the laser energy density is beyond 100 J mm−3. Porosity can be further reduced below 0.5% by optimizing the laser power and scanning speed. It is found that laser rescanning may eliminate the cracks without modifying the grain morphology, crystallographic texture, and phase distribution.

Effect of Sintering Temperature and Solution Treatment on Phase Changes and Mechanical Properties of High-Nitrogen Stainless Steel Prepared by MIM

High-nitrogen stainless steel (HNSS) has been widely concerned and studied owing to its excellent mechanical, corrosion resistance, and biocompatibility properties. A series of HNSS was prepared by metal injection molding (MIM) using gas atomized Fe-Cr-Mn-Mo-0.3 N duplex stainless steel powders. Both sintering and solution treatments were carried out in an N2 atmosphere. The effects of nitrogen distribution and phase transformation on the mechanical properties of MIM HNSS during sintering and solution were studied. The results show that as the sintering temperature increased, the sample density increased, but the total nitrogen content decreased. Nitrogen and Cr2N concentration gradients along the cross-section of as-sintered samples were formed after cooling. The high nitrogen content promotes the decomposition of γ: γsaturated translated to γ and Cr2N. Meanwhile, the low Mn content in austenite also decomposes γ: γ translated to α and Cr2N. After solution treatment, a single γ phase was obtained for samples sintered at 1200 to 1320 °C. For solution treatment samples sintered at 1320 and 1350 °C, their tensile strength was 988.76 and 1036.12 MPa; yield strength was 615.61 and 636.14 MPa, and elongation was 42.58 and 40.08%, respectively. These values vastly exceeded the published MIM HNSS values.

Reassessment of mobility parameters for Cantor High Entropy Alloys through an automated procedure

An automated assessment procedure is performed in order to establish a sophisticated kinetic data bank, introduced and modified by applying consequential iteration steps through the cross-validation method. The nonlinear curve-fitting of the end-member parameters is replaced by a simple linear fitting function via the logarithmic form of the Arrhenius equation. The applied modifications allow us to increase the precision of the method by decreasing the fitting errors. The input data employed here are the tracer diffusion coefficients in the well investigated high entropy alloy Co–Cr–Fe–Mn–Ni. The resulting parameters are in an acceptable agreement with the previously defined parameters in the literature while providing an efficient robust tool for kinetic data base development so that it enable an adequate prediction of diffusion transport.