MX Phase Research Articles

Microstructural Evolution of P92 Steel with Different Creep Life Consumptions After Long-Term Service

P92 steel is widely used in ultra-supercritical units due to its excellent high-temperature performance. This paper studies the microstructure of P92 steel steam pipes in three conditions: as-supplied, after 80,000 h of service at 67.06 MPa stress, and after 100,000 h of service at 80.28 MPa stress. After prolonged service, the P92 steel retains its martensitic structure, but the lath width increases and the dislocation density decreases. In addition to M23C6, MX, and Laves phases, Z phase was also observed among the precipitates. The results indicate that the sizes of M23C6 and Laves phases increase with the progression of creep life consumption, with the coarsening rate of Laves phase being significantly higher than that of M23C6. However, the coarsening of MX phase is not evident. Compared to the Laves phase, the formation of the Z phase requires a longer period of time. The precipitation of the Z phase consumes MX carbonitrides, and it has been observed that the Z phase precipitates from the MX phase, with the two phases exhibiting a coexisting state.

Influence of Ageing Treatment on Microstructure and Mechanical Properties of GH4169 Alloy Prepared Using Wire Arc Additive Manufacturing

The effects of solid-solution and ageing treatments on the microstructure and mechanical properties of a GH4169 alloy made by wire arc additive manufacturing, micro-casting, and forging were researched. The microstructure, along with the size and type of precipitated phase, were analysed using an optical microscope, scanning electron microscope, and transmission electron microscope. The strength and toughness were tested using a tensile testing machine. The results show that a polygonal austenite microstructure was obtained for the GH4169 alloy prepared through wire arc additive manufacturing, micro-casting, and forging, followed by solid-solution and double-ageing treatments at different times. There were a few twins in the austenite matrix. A large number of nano-sized γ″- and γ′-precipitated phases and a small number of Laves phases and MX phases were found in the matrix. The tensile strength and yield strength of the GH4169 alloy increased first and then decreased with the ageing time. After ageing for 16 h, the maximum yield strength was 1287 ± 22 MPa, the maximum tensile strength was 1447 ± 19 MPa, and the elongation was about 19.5%. The main strength mechanism is precipitated phase strength and solid-solution strength. The fracture exhibited obvious ductile fracture characteristics.

Long-term thermal aging effects in ferritic-martensitic steel HT9

The ferritic-martensitic steel HT9 is a candidate material for fuel cladding and core components in advanced nuclear reactors, such as sodium-cooled fast reactors, thanks to their high temperature mechanical properties and low susceptibility to irradiation induced swelling phenomena. However, thermal stability and elevated temperature microstructural evolution in these alloys may impact their long-term behavior and reliability. In this work, the effects of thermal aging on the microstructural and mechanical properties of HT9 have been investigated through complementary electron microscopy, synchrotron X-ray diffraction, microhardness, and thermodynamic modeling. Plates of HT9 were aged up to 50 kh at relevant sodium-cooled fast reactor operational temperatures (360 °C - 700 °C). Trends in microstructure as a function of aging time and temperature were apparent from qualitative and quantitative analysis. These observations were further supported by thermodynamic modeling of the bulk and precipitate phases. Specific phases observed include BCC Fe, FCC M23C6, HCP and FCC MX phase and Laves M2X phase. Through the application of our multi-scale and multi-modal approach, clear information on the aging mechanism of HT9 was obtained, allowing for a more informed prediction, and understanding of the long-term behavior, performance and thermal stability of ferritic-martensitic alloys exposed to elevated temperatures.

Identification of nano-sized precipitates in CLAM steel induced by 3.5 MeV Fe13+ ion irradiation

Nano-sized precipitate phases in normalized-and-tempered CLAM steel (HEAT-0912) before and after 3.5 MeV Fe13+ ion irradiation at 400 °C to 0.61, 1.29 and 2.77 dpa were studied using transmission electron microscope and high-resolution transmission electron microscope. Six types of nanoprecipitate phases based on Cr23C6, TaC, Ta3C2, VC, Cr7C3, and V2C were identified in unirradiated steel. During irradiation, a large number of nanoprecipitates uniformly distributed in the matrix occurred, and the number density of nanoprecipitates initially increased and subsequently decreased with increasing the irradiation dose. Nanoscale Cr-rich M23C6, V-rich MX and M2X phases but no nanoscale phases based on TaC, Ta3C2 and Cr7C3 were identified in the steel irradiated up to 2.77 dpa. After irradiation, five types of irradiation-induced nanoscale new phases were identified in the irradiated steel. These include Fe-rich M3X2 (Cr3C2 types I and II) carbonitrides with the same simple orthorhombic lattice and totally different lattice parameters (approximately a/b/c = 1.146/0.552/0.2821 nm and 0.285/0.925/0.696 nm), Fe-rich M2C, M3C and M5C2 carbides, but the occurrence of which under irradiation varied with the irradiation dose. Fe-rich M3X2 (Cr3C2 type I) and Fe-rich M5C2 phases were identified in the steel irradiated up to 1.29 dpa and only to 2.77 dpa, respectively. Fe-rich M2C and M3C in addition to Fe-rich M3X2 (Cr3C2 type II) phases were identified in the steel irradiated up to 2.77 dpa. The irradiation-induced Fe-rich M3X2 (Cr3C2 type I & II), M5C2 and M2C precipitates appear to be identified, for the first time, in reduced activation ferritic/martensitic steels including CLAM steel. The formation mechanism of these irradiation-induced precipitate phases is also discussed.

Effect of pre-precipitation thermomechanical treatment on precipitation behavior of CLAM steel

China Low Activation Martensitic steel (CLAM) is a cladding material used in thermonuclear fusion reactors. Its high temperature performance is closely related to precipitation strengthening. The MX phase with strong thermal stability is the key to improving the high temperature performance of CLAM steel, and the M23C6 phase which is easy to coarsen under long-term high temperature service conditions is one of the important factors causing creep failure. In order to increase the content of MX phase and reduce the content of M23C6 phase, this paper first pre-precipitates near the precipitation temperature of M23C6 phase (which is also close to the maximum precipitation temperature of MX phase), which limits the precipitation of M23C6 phase and promotes the maximum precipitation of MX phase. Then the subsequent thermomechanical treatment (TMT) is carried out. The results show that the content of M23C6 phase in the samples after pre-precipitation TMT is greatly reduced, and the size is slightly reduced compared with the samples with only thermal deformation. The size of the MX phase is reduced by 10.6%, the volume density is increased by 88%, the volume fraction is increased by 34.1%, and the dislocation density is slightly increased. At the same time, it was found that a large number of MX phases precipitated at the lath boundary and pinned the boundary, which delayed the coarsening of the lath during tempering. The changes of these microstructures improve the precipitation strengthening, dislocation strengthening and boundary strengthening, so the room temperature tensile properties and high temperature tensile properties are improved, but the work hardening makes the total elongation and room temperature impact properties decrease.

Enhanced disperse Ta(C, N) precipitation in reduced activation ferritic/martensitic steels by optimized two-step austenitizing

High-density MX precipitates block the movement of dislocations during creep at high temperature and increase sink strength to point defects under irradiation. Therefore, the precipitation control of MX phase is crucial for the advancement of reduced activation ferritic/martensitic (RAFM) steels. In this paper, an optimized two-step austenitizing strategy was proposed to enhance Ta(C, N) precipitation in RAFM steels, and the temperature effects of the first and second austenitizing on the Ta(C, N) precipitation enhancement were studied. During the first austenitizing, Ta(C, N) particles with a small radius (∼12 nm) and a high number density (∼8.5 × 1019 m−3) precipitated by heterogeneous nucleation on the M23C6 phase boundaries retained by the comparatively low temperature (900 °C). Then in the second austenitizing, enhanced Ta(C, N) precipitates kept good size and thermal stability below 1050 °C. Compared to RAFM steels treated by conventional normalizing and tempering, the strength and creep performance were significantly improved by the pinning effect of the enhanced dispersed Ta(C, N) particles. Furthermore, the optimized two-step austenitizing strategy was validated in the other two RAFM steels, showing broad application prospects in RAFM and heat-resistant steels.

Microstructure refinement and enhanced mechanical properties of wire arc additively manufactured RAFM steel via post heat treatments

Reduced activation ferritic/martensitic (RAFM) steel with high strength and neutron radiation damage resistance is deemed one of the promising structural materials for fusion blankets. In this study, RAFM steel tube was prepared through wire arc additive manufacturing, and the evolution of phase composition, microstructural features and mechanical properties during the as-built and heat treatment processes were investigated. The results show that the as-built state is predominantly composed of α-Fe, and the microstructure's morphology from bottom to top consists of alternating columnar grain regions, equiaxed coarse grain regions, and fine grain regions. Normalizing and tempering treatment eliminates the heterogeneous microstructure, resulting in the presence of M23C6 carbides enriched with Cr and W, as well as MX phases enriched with Ta and V. Partitioning heat treatment results in the formation of ultrafine martensitic, quenched martensite and bainitic microstructures. The mechanical properties of wire arc additively manufactured RAFM steel are influenced by variations in microstructure. The coarse-grained region formed in the as-built state represent weak links. Normalizing and tempering treatment reduces the strength while improving ductility. Partitioning heat-treated RAFM steel exhibited a high strength of 1.1 GPa and an elongation of approximately 10.9%. This study provides a method of combining additive manufacturing with heat treatment to enhance the strength and ductility of RAFM steel simultaneously.

Evolution of the second phases in the weld seams of 2.25Cr-Mo-0.25 V steel in different heat treatment states

Abstract The evolution characteristics of the second phases in the weld seams of 2.25Cr-Mo-0.25 V steel in three states – welded, post-weld heat-treated and creep states – during manufacturing and service were evaluated by calculations and observations using optical microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction spectrometry. The results showed that the second phase was M 3C in the as-welded state. The types and quantities of the precipitated phases increased greatly after post-weld heat treatment (PWHT), and M 3C, M 2C, M 7C3, M 23C6 and MX were the main precipitated phases. During PWHT, the amount of M 7C3 decreased, the amounts of M 23C6 and MX increased, and the sizes of the second phases increased. The precipitates coarsened after long-term creep, and M 7C3, M 6C, M 23C6, M 2C, and MX were the main precipitate phases in this state. The size of the MX phase remained relatively stable during long-term creep, which contributed greatly to the creep resistance.

On the effect of tempering temperature on the long-term creep behavior of a 10% Cr steel with low nitrogen and high boron contents

The effect of a decrease in the tempering temperature from 770 to 750 °C on the long-term creep behavior of a 10% Cr martensitic steel with 0.008 wt % B and 0.003 wt % N was studied. The evolution of microstructure and precipitation distribution during creep was examined using the interrupted tests under an applied stress of 120 MPa at 650 °C. It was found that a higher dislocation density, a finer lath structure and finer carbides after tempering at 750 °C did not provide higher long-term creep strength than after tempering at 770 °C. The creep rupture time was about 30% shorter. Effect of changes in the dislocation density, lath width, sizes of M23C6 carbides and Laves phase particles, and precipitation of V-rich MX phase on the strengthening contribution at the onset of creep and at the transient, apparent steady-state and tertiary stages was analyzed. The higher dislocation density formed by the tempering at a lower temperature provided a higher climb velocity at the transient creep stage. The higher driving force for recovery was not fully compensated by the higher strength exerted by smaller M23C6 carbides. This led to faster annihilation of the lath boundaries and a decrease in internal stress and, consequently, to an order of magnitude higher minimum creep rate of the steel after tempering at 750 °C as compared to tempering at 770 °C.

Long-term creep behaviours and structural stabilities of austenitic heat-resistant stainless steels

ABSTRACT For heat resistant alloys, long-term structural stability at high temperatures is a critical issue for alloy design and applications. In this paper, the long-term creep behaviours and structural stabilities of six heat resistant high Ni alloys and austenitic stainless steels have been studied. The longest creep rupture life is up to 359 283 hours. High Ni and Cr alloys show a good combination of high creep and oxidation resistances. Precipitation of nano MX particles with a very low growth rate improves long-term creep resistance at high temperatures. Long-term stable multiple nanoprecipitates of MX, Cu-rich, Laves and M23C6 phases can greatly contribute to the creep strength. Low Ni austenitic stainless steels show comparatively low oxidation and creep resistances. It was first found that at 800°C, Cr2N could form in the low Ni steel with a long-term crept by the absorption of nitrogen from the air into the matrix.

High/very-high fatigue properties and microstructure evolutions of 9Cr3W3Co turbine rotor steel at room temperature and 650 °C

The study aimed to investigate the high and very-high fatigue properties of 9Cr3W3Co turbine rotor steel at room temperature (RT) and 650 °C. The resulting S–N curves demonstrated a continuous downward trend, without exhibiting a conventional fatigue limit. The fatigue strength corresponding to 5 × 107 cycles is approximately 53.9% of yield strength at RT, increasing to around 55.4% at 650 °C. Meanwhile, compared to the fatigue strength at 5 × 107 cycles at RT, it at 650 °C decreased by 53.3%. Surface crack initiation was found to be the main fatigue fracture failure model, observed at both RT and 650 °C. Microscopic analysis revealed that severe dislocation motion and grain deformation occurred within the material matrix during the cyclic loading process at both RT and 650 °C, resulting in the formation of abundant low-angle grain boundaries, dislocation lines and sub-grains. At RT, the presence of the M23C6 precipitated phase imposed a strong pinning effect, while the MX phase within the martensite laths effectively impeded the movement of dislocation lines, thereby enhancing fatigue properties. However, at 650 °C, the emergence of newly precipitated Cu-rich phases was observed, which can reduce the free path of dislocations, hinder slip motion of dislocations, and thus compensate for the negative effect caused by high-temperature microstructural degeneration.

Precipitation Behavior of the Second Phase in High-Nitrogen Austenitic Stainless Steel Alloyed with V and Nb

The retaining ring is one of the components with the highest stress on the rotor of the turbine generator. Due to the high content of alloying elements in this type of steel, it is extremely easy to precipitate a large amount of the second phase during the forming process of a material, which deteriorates the processability, Therefore, it is very important to study the second phase precipitation of high-nitrogen steel. This work addresses the precipitation behavior of the second phase in a high-nitrogen austenitic stainless steel alloyed with V and Nb. The optical microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffractometry were applied to investigate the influence of heat treatment parameters on the morphology and composition of the precipitated particles. The addition of V and Nb results in the formation of NbVN and VN particles, of which the amount is slightly decreased after a subsequent solution treatment at 1200 °C for 1 h. The results demonstrate that an additional aging treatment at 800~1000 °C for three leads to the participation of lamellar Cr2N and the undissolved MX phase. The content of the precipitates increases with increasing both the aging temperature and the aging time. The addition of V/Nb elements effectively improves the stability of MX phase, and the existence of high energy zones (the MX phase interface and grain boundary) promotes the early formation of Cr2N. Cr2N is shown to nucleate in the high energy zones, which thereafter grows into austenite grains, demonstrating a normal discontinuous cellular growth.

Theoretical screening, intrinsic brittleness and thermal properties of the S-containing MAX carbides and borides

To respond the recent experimental advances, the phase stability, mechanical properties, phonon as well as infrared- and Raman-active modes, thermal expansion and heat capacity were investigated by density functional theory for the S-containing MAX carbides and borides (M from III B to VIII B), of importance, well consistent with the available experimental results. After examining the thermodynamic competition with all the competing phases and intrinsic stability by their lattice dynamics, 18 MAX phases were screened out from 138 ones. Using the “bond stiffness” model as well as the associated criterion for damage tolerance and fracture toughness, the ratio of bond stiffness of weakest M−S to the strongest M-X bonds (kmin/kmax) over 1/2 indicates their intrinsic brittleness of all S-containing MAX phases except Nb4SC3. Including the contributions from phonon and electrons, their linear thermal expansion coefficients [(8.1–13.6)×10−6 K−1, 300–1,300 K] and heat capacities (Cp) as a function of temperature are predicted. Of much interest, a well-established relationship between molar Cp of the MAX and MX phases is theoretically deduced in the present work.

A physically-based constitutive model for a novel heat resistant martensitic steel under different cyclic loading modes: Microstructural strengthening mechanisms

Cyclic responses of a novel heat resistant martensitic steel, 9Cr3Co3W1CuVNbB steel, under different loading modes were studied to reveal its complex strengthening mechanisms at high temperature. Based on the experimental observations, dislocation strengthening, precipitation strengthening by M23C6 phase, MX phase, and Cu-rich phase, and subgrain boundary strengthening were the main mechanisms for its excellent fatigue and creep-fatigue properties. In particular, the dynamic process of interaction between phase and dislocation were studied with the help of molecular dynamics method, and the different contributions of hard and soft phases in the studied steel were determined in fatigue and creep-fatigue loading. Based on these phenomena, a physically-based constitutive model was proposed for both fatigue and creep-fatigue (dwell fatigue at elevated temperature) tests considering various micromechanical mechanisms. Three ways for dislocation annihilation were proposed to simulate the dislocation evolution under different loadings. In addition, the effect of Cu-rich phase was modeled by critical breaking angle and dislocation line tension. The capability of the proposed model under different loading modes was verified by comparing cyclic responses, hysteresis loops, stress relaxation, and dislocation density evolution. The proposed model provides an alternative perspective on understanding fatigue and creep-fatigue behaviors of heat resistant martensitic steels owning the similar strengthening mechanisms.

Effect of Si content on the microstructure and mechanical properties of 9Cr-ferritic/martensitic steels

9Cr-F/M−xSi (x = 0–1.0 wt%) steels were fabricated through vacuum induction melting technique and processed by hot forging, hot rolling, normalizing and tempering, subsequently. Their microstructure and mechanical properties were characterized using OM, SEM, TEM, Vickers hardness tester and tensile tester. The steel has a typical ferrite/martensitic structure, with M23C6 and MX phases precipitated at the martensite lath boundary or in the lath. With Si content increasing, the average ultimate tensile strength (UTS) and hardness of 9Cr-F/M−xSi increase simultaneously from 678 MPa and 235 HV for 9Cr-F/M−0Si steel to 788 MPa and 265 HV for 9Cr-F/M−1.0Si steel, respectively, while the total elongation kept almost constant at 22.5%. The main strengthening mechanism is the solid solution strengthening due to silicon addition and the change in the carbide precipitation behavior caused no remarkable hardening contribution. These results can provide a reference for the composition design of structural materials for nuclear reactors.

Microstructure Evolution and Mechanical Behaviors of P92 Steel Welded Joint with Repetitive Post Tempering

The microstructure evolution and mechanical properties of P92 steel welded joint have been systematically investigated relating to the number of tempering cycles. Martensite laths, M23C6 precipitates, and tiny MX phase have been characterized in P92 base metal (BM). Likewise, the heat‐affected zone (HAZ), fusion zone (FZ), and weld metal (WM) show the similar feature of phase composition to the BM. However, δ‐ferrite patches can be found in FZ. With the increasing number of tempering cycles, the area fraction and average size of M23C6 precipitates gradually increase in HAZ and FZ despite that microstructure has little change. Consequently, the hardness, ultimate tensile strength, and yield strength tend to decrease, while the elongation can be improved in some degree. The reduction in solution strengthening, grain refinement strengthening, and precipitation strengthening is responsible for the strength degeneration of P92 steel welded joint with reduplicative tempering.

Irradiation-induced phases in an Fe ion irradiated CLAM steel

CLAM (HEAT-9) steel samples were subjected to a standard heat treatment involving a normalizing for 0.5 h at 980 °C and a tempering for 1.5 h at 760 °C. The standard heat-treated steel samples were irradiated with 3.5 MeV Fe13+ ions at 400 °C to 0.53 dpa and 0.61 dpa. The precipitate phases of standard heat-treated steel samples and the irradiated steel samples were observed and analyzed using transmission electron microscopies and energy dispersive X-ray spectrometers. Through the analyses of selected-area electron diffraction pattern and energy dispersive X-ray data of thin foil specimens, the effects of irradiation on the main inherent precipitate phases, Cr-rich M23C6 and Ta-rich MX, in standard heat-treated steel were investigated, and three kinds of phases induced by the irradiation were found in the irradiated steel. After irradiation, Cr-rich M23C6 and Ta-rich MX phases were observed and confirmed to be still present in the steel, but the Cr/Fe ratio and W content in the Cr-rich M23C6 precipitates decreased obviously. These three irradiation-induced phases in the irradiated steel were identified as Fe-rich M3C carbide with a simple orthorhombic crystal structure, sigma-FeCr intermetallic compound with a body-centered tetragonal crystal structure, and Fe-Cr binary intermetallic compound with a body-centered cubic crystal structure. The identified Fe-rich M3C/sigma-FeCr/Fe-Cr phases have a metal element composition of 92–98Fe and 2–8Cr/85–95Fe and 5–15Cr/40–90Fe and 10–60Cr (in at.%), and a size range of 80–190/60–190/70–300 nm, respectively. The formation of these three irradiation-induced phases in the steel are also discussed.

Impact toughness of a 12% Cr martensitic steel: Conventional heat treatment vs. thermo-mechanical processing

The impact toughness together with determination of the ductile–brittle transition temperature for the 12 %Cr steel with the low N and high B contents subjected to conventional heat treatment and thermo-mechanical processing have been investigated. The thermo-mechanical processing includes the interim hot forging and long-term annealing at 1050 °C with the aim to dissolve the delta-ferrite and coarse W-rich particles, as well as to decrease the particle number density of M23C6 carbides along the lath boundaries and to precipitate V-rich MX phase. The temperature dependence of Charpy energy curves including upper and lower shelf energy is found to be shifted in a side of higher energies. The ductile–brittle transition temperature decreases from 70 °C to (45–50)°C.

APT characterization of irradiation effects on MX phase in reduced-activation ferritic/martensitic steels

Reduced activation ferritic/martensitic steels (RAFMs), such as Eurofer 97 and F82H, are designed to enhance the high-temperature strength by forming the fine dispersive particles of the MX phase. However, the stability of MX phase is still not fully understood. The objective of this study is to determine irradiation effects on the MX phase of Eurofer 97 and F82H. The irradiation experiments were performed at the Swiss Spallation Neutron Source (SINQ) at a temperature of ∼300 °C to a dose of ∼20 dpa. The current work reveals the irradiation effect on the MX phase on an atomic scale by atom probe tomography (APT). The irradiation on the one hand can affect the composition of the MX phase, on the other hand, induces interface segregation. Compared with the nitride in the unirradiated Eurofer 97, the nitride in the irradiated specimen contains less V and Ta, while more Cr, Fe, Mn, and W. The irradiation-induced segregation shows consistency among different interfaces between the MX nanoprecipitate, the matrix and the M23C6 precipitate that the undersized elements, Mn, Si, and Cu are enriched, oversized elements W, V and Ta are depleted, while the spallation transmutants Ca, Sc, and K, being largely oversized elements, enriched at the phase boundary as well. The irradiation-induced changes of the MX phase indicates that in the current irradiation condition the MX phase endures an initial transformation process to Z-phase and in the meanwhile a dissolution process at the edge. Ta in the RAFM steels plays a similar role as Nb in the conventional ferritic/martensitic (FM) steels during the MX phase to the Z-phase transformation process where Nb diffuses out of the MX phase.

Effect of B-Si ratio and laser remelting on the microstructure and properties of Fe10Co10Ni10Cr4Mo6BxSi10-x coating by laser cladding

High-entropy alloy coating has huge potential application values in improving the service life of the friction parts. The effects of the B-Si ratio and laser remelting on the microstructure, phases, mechanical and wear properties of the laser cladding Fe10Co10Ni10Cr4Mo6BxSi10-x coatings were investigated. When x equals 10, the coating crystalizes in a FCC structure together with lots of MxB phases. Si element adding promotes the formation of BCC phase of Fe10Co10Ni10Cr4Mo6BxSi10-x coatings with the appearance of new MxSi and MxBSiy phases, but prevents the formation of MxB and MxBSiy with the decrease of B-Si ratio. When x drops to zero, the microstructure of the coating transforms into a BCC with tiny amounts of FCC and MxSi phase. With the increase of Si element content, Mx(B, Si) standing for any combination of MxB, MxSi and MxBSiy phases decrease. The lowest friction coefficient (0.3786) and wear volume loss (2.46 × 106 μm3) show that Fe10Co10Ni10Cr4Mo6B5Si5 coating has the best wear resistance because of a higher toughness and values of H/E and H3/E2. Laser remelting once reduces the component segregation of the coating, and promotes the formation of BCC and Mx(B, Si) phases. The wear resistance of the coating increases with the improvement of its wear characteristics (H/E, H3/E2 and η). However, when the coating is remelted twice, the wear resistance decreases due to the drop of the hardness and wear characteristics attributed to the dominant position of FCC structure. Fine and uniform microstructure, and proper proportion of hard phases (BCC and Mx(B, Si)) and soft phase (FCC) can increase the mechanical properties and wear resistance of Fe10Co10Ni10Cr4Mo6BxSi10-x coatings.