Tungsten Steel Research Articles

Ion-induced electron emission by keV-range energy indium ions: Influence of material and geometry

This work provides measurements of the ion-induced electron emission yield caused by keV-range energy indium ions (3–8 keV). In our experiment, the ion sources, fueled with indium, are based on the working principle of field-emission electric propulsion (FEEP) technologies. The measured yields are given for different material properties (plain structure vs foam) and geometries (flat surface vs conical). Study outcomes show that electrons induced by keV-range indium ions can lead to overestimating the measured ion current by 30%–200% depending on the collector materials and geometry. We spotlighted that molybdenum, tungsten, and stainless steel 316L have relatively low yields compared to aluminum 2017A. Moreover, it is possible to lower down a specific material yield by two-thirds when using a foam structure. Finally, it is shown that off-axis ion influence on a collector increases the resulting electron emission yield. In the case of an indium-FEEP thruster, ion-induced electron emissions are a major perturbation when measuring ion current. Mainly, due to the energy range of ions studied, yields retrieved are orders of magnitudes larger than what is usually measured when studying the plume of an electrostatic electric propulsion system. It is, therefore, strongly recommended to use a so-called Faraday cup to study the ion beam from an indium-FEEP thruster as the probe’s close architecture allows us to greatly mitigate these perturbations.

Influence of sintering time on diffusion bonding of WC-10Co and AISI4340 by spark plasma sintering

It is challenging to obtain successful bonding between cemented tungsten carbide and steel due to the large differences in their physical and mechanical properties. We used spark plasma sintering (SPS) technique and successfully bonded WC-10Co and AISI4340 high-strength steel at a low temperature. The effects of sintering time (5–20 min with a gap of 5 min) on their diffusion bonding were examined. The microstructure of the bonded composite materials was evaluated, and formed phases were identified. The mechanical properties were investigated, and the importance of processing parameters of SPS was discussed. The results show a crack-free continuous metallurgical bonding achieved at 1000°C, and the bonding strength increased with increasing holding times of 5, 10, 15, and 20 min. The sintered WC-10Co powders obtained nearly full density (99.07%) with an average maximum hardness of 1763 HV5. A special arrangement was used to determine the tensile bonding-strength with maximum average of 152 MPa at 20 min.

Solid-State Rotary Friction-Welded Tungsten and Mild Steel Joints

This paper is a study of the microstructure and other selected properties of solid-state, high-speed, rotary friction-welded tungsten and mild steel (S355) joints. Due to the high affinity of tungsten for oxygen, the welding process was carried out in a chamber with an argon protective atmosphere. Joints of suitable quality were obtained without any macroscopic defects and discontinuities. Scanning electron microscopy (SEM) was used to investigate the phase transformations taking place during the friction welding process. Chemical compositions in the interfaces of the welded joints were determined by using energy dispersive spectroscopy (EDS). The microstructure of friction welds consisted of a few zones, fine equiaxed grains (formed due to dynamic recrystallization) and ultrafine grains in the region on the steel side. A plastic deformation in the direction of the flash was visible mainly on the steel side. EDS-SEM scan line analyses across the interface did not confirm the diffusion of tungsten to iron. The nature of the friction welding dissimilar joint is non-equilibrium based on deep plastic deformation without visible diffusive processes in the interface zone. The absence of intermetallic phases was found in the weld interface during SEM observations. Mechanical properties of the friction-welded joint were defined using the Vickers hardness test and the instrumented indentation test (IIT). The results are presented in the form of a distribution in the longitudinal plane of the welded joint. The fracture during strength tests occurred mainly through the cleavage planes at the interface of the tungsten grain close to the friction surface.

Effect of Ni/MoS2 Addition on Microstructure and Properties of Supersonic Plasma-Sprayed Ni-Based Composite Coatings

Abnormal tool wear is a significant problem encountered in machining. MoS2 has the function of friction reduction; thus, to mitigate friction, two Ni-based coatings, Ni60 and Ni60 + 15 wt.% Ni/MoS2, were obtained on tungsten steel using supersonic plasma technology. The microstructure, phase structure, microhardness, fatigue properties, and friction and wear properties of the two coatings were characterized. The results show that the two plasma-sprayed Ni-based coatings have desirable structures. The addition of Ni-coated MoS2 can effectively improve the hardness of the coatings, with values reaching as high as 735 HV. The speed of rotation of the friction ball was set as 200 r/min, and the cutting force was 201.6 N. The fatigue performance as well as the friction and wear performance of the coating are simulated using ANSYS. The fatigue performance is improved by 12.6 % after adding 15 wt.% Ni/MoS2, and the friction system of the coating becomes stable after 25 min of contact. The addition of 15 wt.% Ni/MoS2 can effectively improve the performance of the tool material.

Preliminary studies on detonation sprayed W/W-steel composite coating materials on steel substrates for the first wall of blanket

The mismatch of the thermo-mechanical properties of tungsten and steel would lead to large thermal stress between detonation sprayed (DS) tungsten coatings and steel substrates. DS W-steel composite coatings were prepared on 316 L stainless steel (SS) substrates as the interlayer of DS-W coatings to solve this issue. The DS-W coatings manufactured on 316 L SS substrates without interlayers were used for comparing. The surface and cross-section morphologies showed the composite coating material was dense steel lamellas-stacked structure in which tungsten particles dispersed homogeneously. The EDS and XRD results showed the composite coating was consisted of three different textures: W, SS and W-SS compound alloy. But the tungsten content in the coating was lower than the expected 50 vol% due to the low deposition efficiency of the tungsten powders. The Vickers hardness of the composite coating was 577– 647 HV which was between that of the DS-W and the SS substrate. The bonding strengths of the DS W/W-SS/SS substrate three-layer coating samples and the DS-W/SS substrate coating samples were about 61.33 MPa and 52.45 MPa, respectively. Besides, the three-layer samples had better performance under the transient heat shock tests than that of the DS-W/SS substrate samples. All these results proved the addition of the DS W-SS composite interlayers improved the overall properties of the DS-W/SS substrate system. The relatively low tungsten content in the composite coatings should be optimized to further improve the performance of the three-layer coating system in the following.

Design and Experiment of 1 THz Slow Wave Structure Fabricated by Nano-CNC Technology

This article reports a slow-wave structure (SWS) working at 1 THz which can be fabricated through nano-computer numerical control (nano-CNC) technology for the first time. First, a 1 THz deformed quasi sine waveguide (D-QSWG) SWS has been designed and simulated in this article. To reduce the metal loss of input and output waveguide, a coupler which transit the waveguide to over mode rectangular waveguide has been designed. The simulation result shows that input and output waveguides with this coupler have lower metal loss than that of WR1 rectangular waveguide. To fabricate the designed D-QSWG SWS, tungsten steel endmills have been used. The fabricated SWS has the surface roughness around 58&#x2013;74 nm, the corresponding effective conductivity is around <inline-formula> <tex-math notation="LaTeX">$2\times 10^{{7}}$ </tex-math></inline-formula>&#x2013;1.85 <inline-formula> <tex-math notation="LaTeX">$\times 10^{{7}}$ </tex-math></inline-formula> S/m. And the cold test results show that the insertion loss of the fabricated model is less than 30 dB while the reflection loss is less than &#x2212;15 dB in the frequency range of 0.998&#x2013;1.016 THz, which has a good consistency with the simulated results. The beam-wave interaction simulation results based on the cold test results show that the designed D-QSWG traveling wave tube (TWT) has the output power of 300 mW, and the 3 dB bandwidth is around 3 GHz.

Abnormal interfacial bonding mechanisms of multi-material additive-manufactured tungsten–stainless steel sandwich structure

Tungsten (W) and stainless steel (SS) are well known for the high melting point and good corrosion resistance respectively. Bimetallic W–SS structures would offer potential applications in extreme environments. In this study, a SS→W→SS sandwich structure is fabricated via a special laser powder bed fusion (LPBF) method based on an ultrasonic-assisted powder deposition mechanism. Material characterization of the SS→W interface and W→SS interface was conducted, including microstructure, element distribution, phase distribution, and nano-hardness. A coupled modelling method, combining computational fluid dynamics modelling with discrete element method, simulated the melt pool dynamics and solidification at the material interfaces. The study shows that the interface bonding of SS→W (SS printed on W) is the combined effect of solid-state diffusion with different elemental diffusion rates and grain boundary diffusion. The keyhole mode of the melt pool at the W→SS (W printed on SS) interface makes the pre-printed SS layers repeatedly remelted, causing the liquid W to flow into the sub-surface of the pre-printed SS through the keyhole cavities realizing the bonding of the W→SS interface. The above interfacial bonding behaviours are significantly different from the previously reported bonding mechanism based on the melt pool convection during multiple material LPBF. The abnormal material interfacial bonding behaviours are reported for the first time.

Study of liquid tin-lithium alloy interaction with structural materials of fusion reactor at high temperatures

The paper presents the experimental studies to determine the corrosion compatibility of various base materials of the capillary-porous structures (CPS) with a liquid tin-lithium alloy under high temperatures. The experiments were carried out with Li-Sn alloy and the samples of vanadium, tungsten, molybdenum, tantalum, and stainless steel. These materials were selected as the candidate ones for the matrix of Li-Sn CPS prototypes. Manufacture of Li-Sn alloy and experiments were carried out at test bench VIKA. The ranges of the temperatures was: 600 °C–800 °C for stainless steel, and 850 °C–1000 °C for other metals; exposure time for every temperature step was up to 100 h.The implemented activities included manufacture of Sn-Li alloys with various lithium contents (25 at.% and 27 at.%), characterization of the samples, experiments to study compatibility of liquid tin-lithium with vanadium, tungsten, molybdenum, tantalum at temperatures of 850 °C–1000 °C, and stainless steel at temperatures of 600–800 °C. As a result of the performed activities, molybdenum and tungsten were selected as the most corrosion resistant materials in respect to Li-Sn alloys.

W/EUROFER functionally graded coatings for plasma facing components: Technology transfer to industry and upscaling

The tritium breeding blanket is a vital component of future fusion reactors, providing the fuel for the fusion reaction. Tungsten is a viable coating material to protect its first wall from erosion by plasma. The feasibility of applying tungsten coatings by vacuum plasma spraying has already been demonstrated, using a functionally graded material of mixed tungsten and EUROFER97 steel as connecting layer to mitigate a thermal expansion mismatch. This technology was now transferred to industrial level to enable further upscaling. Samples of three different sizes were coated, the largest ones measuring 500 × 250 mm² and containing mock-up cooling channels. The sample distortion was found to be small. An ultrasonic analysis did not reveal any delamination but indicated potential weaker spots in the corners that may have been subjected to faster cooling. Both the coating's thickness of 2 mm and linear chemical gradation over five interlayers met well with specifications, as verified by scanning electron microscopy, energy-dispersive X-ray spectroscopy as well as image thresholding analysis. The microstructure consisted of typical splat-shaped particles of tungsten and EUROFER, with minor porosity only. In total, these first results indicate that good coating quality can be achieved even in dimensions approaching fusion-relevant size.

Mechanical Properties and Microstructure of TIG and ATIG Welded 316L Austenitic Stainless Steel with Multi-Components Flux Optimization Using Mixing Design Method and Particle Swarm Optimization (PSO).

In this study, the effects of pseudo-ternary oxides on mechanical properties and microstructure of 316L stainless steel tungsten inert gas (TIG) and activating tungsten inert gas (ATIG) welded joints were investigated. The novelty in this work is introducing a metaheuristic technique called the particle swarm optimization (PSO) method to develop a mathematical model of the ultimate tensile strength (UTS) in terms of proportions of oxides flux. A constrained optimization algorithm available in Matlab 2020 optimization toolbox is used to find the optimal percentages of the selected powders that provide the maximum UTS. The study indicates that the optimal composition of flux was: 32% Cr2O3, 43% ZrO2, 8% Si2O, and 17% CaF2. The UTS was 571 MPa for conventional TIG weld and rose to 600 MPa for the optimal ATIG flux. The obtained result of hardness for the optimal ATIG was 176 HV against 175 HV for conventional TIG weld. The energy absorbed in the weld zone during the impact test was 267 J/cm2 for the optimal ATIG weld and slightly higher than that of conventional TIG weld 256 J/cm2. Fracture surface examined by scanning electron microscope (SEM) shows ductile fracture for ATIG weld with small and multiple dimples in comparison for TIG weld. Moreover, the depth of optimized flux is greater than that of TIG weld by two times. The ratio D/W was improved by 3.13 times. Energy dispersive spectroscopy (EDS) analysis shows traces of the sulfur element in the TIG weld zone.

Scaling of deuterium retention in

In continuation of earlier work on 3 MeV proton-damaged tungsten and reduced-activation steels we present new results on Eurofer97, Beryllium and W-5%Re sintered alloy irradiated <400 K. Methodical improvements result in largely reduced uncertainties. Beryllium is loaded using a 5 kV D2 + ion-source to 6.3*1021 D m−2 at 300 K. Eurofer97 and W-5Re are loaded in PSI-2 to 3*1025 D m−2. Irradiation and D-loading are conducted at ∼400 K. The D retention is measured by 3He μ-NRA. An exponential saturation fits the W-5Re D-retention data with R2 = 0.99 . The retention increases by a factor 10.3 in W-5Re, similar as in W, but on a ~7 times lower level. Within ±25% uncertainty D Retention in Eurofer97 proves to be independent of displacement damage up to 6.3 DPA. Beryllium shows increased retention by a factor 3 up to the tested maximum of 0.08 DPA. The retention in beryllium starts saturating, but the limited DPA range allows fitting the data with exponentials and power-laws.

Improving the precision of micro-EDM for blind holes in titanium alloy by fixed reference axial compensation

Abstract During the electrical discharge machining (EDM) process, the tool electrode wear is inevitable, which affects the process precision of the micro-hole. In the present experimental investigation, a fixed reference axial compensation (FRAC) method is proposed to enhance the machining precision of micro-hole. The effect of pulse power, compensation methods, and electrode materials on the depth and roundness factor of micro-hole are explored. The experiment results show that the FRAC method can realize the accurate compensation and reach the expected depth hole processing. When the FRAC is used, the depth deviation is less than 0.43%, and the minimum difference from the expected depth is only 0.106 µm. In addition, the micro-holes of tungsten steel and brass electrodes machine by the FRAC method were close to the expected depth, the difference from the expected depth less than 0.7%, but the bottom of micro-hole produced a cone. However, compared to tungsten steel and brass electrodes, the copper electrode has a better processing performance, the roundness factor is up to 79.8%. When the long-pulse power supply is applied, the expected depth of 400–1,600 µm blind holes with a better processing shape, and the phenomenon of the cone at the bottom are not apparent. Therefore, the proposed FRAC method can be utilized in many high-end manufacturing fields to improve the precision of the micro-hole for micro features.

Bonding strength evaluation of explosive welding joint of tungsten to ferritic steel using ultra-small testing technologies

The interface bonding strength of thinly coated materials is difficult to be measured accurately owing to the size limitations of the coating layer. In this study, the interfaces bonding strength of an underwater explosive welded tungsten foil on ferritic steel was investigated by deep-notch-type micro-tensile tests and microscopic double-notch shear (DNS) compression tests. The micro-tensile tests were carried out using a focused ion beam (FIB) tensile system. The results showed that the tensile strength of the interface region near the ferritic steel was larger than that of the ferritic steel but weaker than that of the tungsten foil. The micro-DNS compression tests were conducted in both the tungsten and interface regions. The obtained shear strength of tungsten exhibited a strong size dependence as follows: the smaller the size, the higher the strength. Although interface specimens with a large gauge section area showed a shear strength similar to that of tungsten DNS specimens, an interface region specimen with an area of the gauge section of approximately 1 μm² showed larger shear strengths (∼4.8 GPa) than the tungsten region (3.2 GPa). Observations of the bonding microstructure and fracture surface indicated that the obtained shear strength with 1 μm² specimens corresponded to the interface bonding shear strength between tungsten and ferritic steel obtained by underwater explosive welding.

Experimental Study on the Influence of Tool Electrode Material on Electrochemical Micromachining of 304 Stainless Steel.

Different cathode materials have different surface chemical components and machining capacities, which may finally result in different machining quality and machining efficiency of workpieces. In this paper, in order to investigate the influence of cathode materials on the electrochemical machining of thin-walled workpiece made of 304 stainless steel, five cylindrical electrodes are used as the target working cathodes of electrochemical machining to conduct experiments and research, including 45# steel, 304 stainless steel, aluminum alloy 6061, brass H62, and tungsten steel YK15. The stray current corrosion, taper, and material removal rate were used as the criteria to evaluate the drilling quality of efficiency of a thin-walled workpiece made of 304 stainless steel. The research results show that from the perspectives of stray current corrosion and taper, aluminum alloy 6061 is an optimal tool cathode, which should be used in the electrochemical machining of thin-walled workpieces made of 304 stainless steel; on the aspect of material removal rate, the 45# steel, 304 stainless steel, and aluminum alloy 6061 present close material removal rates, all of which are higher than that of brass H62 and tungsten steel YK15. Based on comprehensive consideration of both machining quality and machining efficiency, the aluminum alloy 6061 is the best option as the cathode tool in the electrochemical machining of thin-walled workpieces made of 304 stainless steel.

Enhanced directional detection of gamma sources

Radiation measurement is an effective way to detect and locate nuclear threats. Moving the detector and monitoring the count rate during searches is a common way for finding the source. To minimize exposure and prevent operators from getting too close to the source, an alternative method for locating the source by occlusion is devised. This work explores the use of two NaI detectors and an absorber for estimating the direction of a radiation source. Measurements were carried out for the source located between 0° and 90° in 15° intervals. The ratios of total counts in the detector, counts in the full-energy peaks, and mean energy of the energy spectrum for the far-side detector to the near-side detector as a function of angle are studied for 57Co, 60Co, 137Cs, and 232Th sources. Comparisons are made for placing a piece of tungsten or stainless steel plate between the two detectors with no absorber. When a metal plate is sandwiched between two detectors, the counts in the energy spectra change more quickly between the two detectors with the source angle. Furthermore, the gamma attenuation for tungsten is higher than stainless steel. As a result, the occlusion by tungsten is more effective and useful for estimating the source direction. The 232Th data were also analyzed by dividing the energy spectrum into three windows to examine the ratio of counts in each window between the two detectors. It is found that the source direction of 137Cs and 60Co can be deduced by using the 232Th data as a reference. In order to reduce the size, weight, and power for man-portable and unmanned systems, it is feasible to use only two detectors and a metal plate inserted in-between to quickly obtain the direction of a radiation source.

Foreign object damage tolerance and fatigue analysis of induction hardened S38C axles

Flying ballast impact damage on railway axles poses a threat to structural integrity and safety of high-speed trains. A comprehensive evaluation on the fatigue strength debit of axles with foreign object damage (FOD) is vital for their safe operation and maintenance under damage tolerance philosophy. In this study, FODs were simulated by shooting tungsten steel balls to the specimens extracted from surface induction hardened S38C axles. Specifically, tests were performed under three impact velocities, i.e. 200, 300 and 400 m/s, and five incident angles for each impact velocity. Morphologies of impact damage were observed by scanning electron microscope (SEM) as well as the cross-sections. Fatigue strength of impacted specimens were then evaluated. Results show that depth and volume of damaged zone increases with the incident angle at the velocity of 200 m/s. Fatigue strength losses of specimens impacted at velocities of 300 and 400 m/s is around 50% compared with that of smooth ones. Fatigue crack originated from the exit rim for 200 m/s glanced impacted specimens, while multiple cracks propagated from both exit rim and bottom of crater impacted at 300 and 400 m/s. Finally, fatigue strength of damaged specimens was evaluated based on the defect depth concept and Kitagawa–Takahashi (K–T) diagram.

Machining characteristics of 65 vol.% SiCp/Al composite in micro-WEDM

Wire electrical discharge machining (WEDM) has been proven as an effective way for machining various hardness conductive materials, such as tungsten steel or particle reinforced metal matrix composite (PR-MMC). However, the machining characteristics of high-volume content (>50 vol.%) silicon carbide (SiC) reinforced aluminum (Al) matrix composite (SiCp/Al) in WEDM are often unsatisfactory due to the frequent wire rupture and unstable processing. Addressing this issue, this paper proposes micro-WEDM to steadily machine 65 vol.% SiCp/Al composite with high process efficiency and adequate good surface quality. The workpiece surface is characterized by SEM, optical microscope, EDS and XRD to clarify the removal mechanism of the SiCp/Al composite which consists of melting, vaporization, shedding, oxidation and thermal decomposition. In addition, the influences of processing parameters on material removal rate (MRR) and surface roughness (Ra) is investigated. Experimental results indicate that MRR increases with the increasing of pules-on time and wire tension, the decreasing of pulse-off time and servo voltage. Ra increases with the increasing of pules-on time, servo voltage and wire speed, the decreasing of pulse-off time. Furthermore, a hybrid optimization method is proposed to obtain the optimal processing parameters combination for fast machining speed with low surface roughness based on support vector machine (SVR) and particle swarm optimization (PSO). Verified experimental results indicate that SVR-PSO optimization algorithm can effectively improve the machining characteristics in WEDM of 65 vol.% SiCp/Al composite. Furthermore, the Pareto optimal solution sets based on the SVR-PSO are found to have high precision and reliability.

Fatigue assessment of EA4T railway axles under artificial surface damage

Foreign object damage (FOD) introduced in service, indentations, and nicks encountered during maintenance are typical defects leading to pre-scrap of high-speed railway axles. A comprehensive assessment of the influence of these defects on the structural integrity of axles is critical for ensuring their operation safety with low maintenance costs. Three types of defects were produced artificially on specimens extracted from EA4T axles, electronic discharge machine (EDM) crater, indentation via compressing balls, and FOD by tungsten steel balls and cubes. Rotating bending fatigue tests were performed for fatigue strength evaluation of smooth and defected specimens. Morphologies of defects and fracture surfaces were studied. EDM defect surface is rough and the secondary notches are the fatigue crack initiation sites, while fatigue crack of indented and impacted specimens initiates from the sharp point of defect rims. Fatigue strength of specimens with indentation or tungsten ball impact damage is superior to that of EDM specimens and cubical projectile impacted specimens under the same depth. A large dispersion was found in the shape of impact damages by cubic projectiles and scattered fatigue strength as a consequence. Except for the defect depth, other parameters including produce modes and shape of the defect, should be considered to give a reliable evaluation on the fatigue strength of defected specimens.

Friction, Wear and Corrosion Behavior of Environmentally-Friendly Fatty Acid Ionic Liquids

This research deals with the tribological behavior and corrosion performance of three novel fatty acid anion-based ionic liquids (FAILs): methyltrioctylammonium hexanoate ([N8,8,8,1][C6:0]), methyltrioctylammonium octadecanoate ([N8,8,8,1][C18:0]) and methyltrioctylammonium octadec-9-enoate ([N8,8,8,1][C18:1]), employed for the first time as neat lubricant with five different material pairs: steel–steel, steel–aluminum alloy, steel–bronze, steel–cast iron and steel–tungsten carbide. These novel substances were previously obtained from fatty acids via metathesis reactions, identified structurally via NMR (nuclear magnetic resonance) and FTIR (Fourier-transform infrared spectroscopy) techniques, and then characterized from a physicochemical (density, water solubility, viscosity, viscosity index and refractive index) and environmental (bacterial toxicity and biodegradability) points of view. The corrosion behavior of the three FAILs was studied by exposure at room temperature, while friction and wear tests were performed with a reciprocating ball-on-disc configuration. The main results and conclusions obtained were: (1) Corrosion in the presence of the three FAILs is observed only on the bronze surface; (2) All FAILs presented similar tribological behavior as lubricants for each tested material pair; (3) XPS (X-ray photoelectron spectroscopy) analysis indicated that the surface behavior of the three FAILs in each material pair was similar, with low chemical interaction with the surfaces.

Structure of high-speed alloy after plasma surfacing in nitrogen and heat treatment

The authors have studied the effect of plasma surfacing and s sequent high-temperature tempering on surface morphology and elemental composition of deposited coatings of high hardness chrome tungsten steel, such as R18, additionally alloyed with aluminum and nitrogen (0.86 % C; 4.84 % Cr; 17.0 % W; 5.40 % Mo; 0.50 % V; 0.65 % Al; 0.06 % N). 30KhGSA steel, which has a complex of high mechanical properties, is used as the base metal. Specific feature of the surfacing was low-temperature preliminary and concurrent heating, as well as thermal deposition cycle, consisting of three main stages. At the first stage with limited heating time and increased cooling rate at high temperatures, grain growth and decomposition of austenite was prevented with formation of equilibrium low-strength structures. At the second stage deposited metal stayed in austenitic state. At the third one, the deposited metal with low tendency to crack has been obtained. Using the method of scanning electron microscopy and X-ray spectral microanalysis, surface morphology and elemental composition of the coatings were studied in two states: immediately after surfacing and in state after surfacing and high-temperature tempering. It has been established that in the first case, the main part of material surface is pearlite grains. At the joints and along grain boundaries, cementite of complex composition and compounds based on iron, tungsten and molybdenum, of variable composition (Fe 4 W 2 N, FeWN 2 and Fe 4 W 2 C) are located. Solid solutions based on aluminum and, possibly, the AlN phase also present. High temperature tempering leads to hardness increase, change in shape and size of grains, quantitative change in elemental composition, and uniform distribution of alloying elements over the volume of material. The proposed method of plasma surfacing with high temperature tempering provides all the basic requirements for the surface of working rolls of cold rolling, which is confirmed by test results of the batch of deposited rolls.