Chemical Composition Of Coatings Research Articles

Energy and environmental applications of ultrasonically sulfur doped copper-nickel hydroxides with heterostructures

A series of sulfur doped copper-nickel hydroxides with heterojunctions were successfully fabricated on nickel foam by adjusting thiourea volume via a facile sonochemical pathway. The effect of volume of thiourea on the final morphology and chemical composition of the hybrids were also investigated by field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy analyses. Furthermore, the electrochemical performance and catalytic activity of the as-obtained hybrids were also investigated. Among the tested electrode, the hybrid material fabricated using 6 ml of thiourea (TU-6) showed outstanding electrochemical properties comprising a high specific capacitance of about 2708 F g−1 at 5 A g−1. In addition, the TU-6 hybrid (catalyst) material displayed remarkable reductive degradation ability towards azo dyes viz., methyl orange (within 8 min) and congo red (within 20 min) in the presence of sodium borohydride (reducing agent) with fast kinetics and good reproducibility, respectively. The exceptional electrochemical performance and excellent catalytic activity of TU-6 hybrid electrode may be attributed to the formation of catalytically active sulfur doped copper-nickel hydroxides (CuS/Ni3S2/NiOOH) three-interface synergistic effect, and unique porous micro-rosette-like texture which increased the diffusion rate and adsorption capacity. The adopted strategy is a simple and generic way for material fabrication to solve the energy and environmental problems.

Metal matrix composites with ternary intermetallic inclusions fabricated by laser direct energy deposition

At the present research, we obtained the metal matrix composites (MMC) of dispersion-reinforced nickel and titanium based alloys with variable content, structure and properties using laser direct energy deposition (LDED). We have ascertained that forming double and triple reinforced MexAly (x,y=1.0.3) intermetallic structures with preset parameters of dispersibility and spatial distribution can be performed in-situ, using the LDED during the phase transformations of cooling and crystallization of the alloy. The preset gradients of final chemical composition, structure and microhardness have been obtained precisely by regulating the composition of the powder mixture supplied to the active zone of the LDED. We suggest a combination method of the LDED which can be an effective instrument for search and development of the new MMC and alloys for the additive manufacture field, as well as for studying structure- and phase-formation in the nonequilibrium conditions of laser synthesis.

Carbon based coatings for applications in friction couples with bearing steel and aluminium alloy

Purpose: Low friction nc-WC/a-C:H coatings deposited by means of magnetron sputtering provide very good tribological properties in friction couple against hard steels and good adhesion to steel substrates. Nevertheless, it was necessary to elaborate a new type of coatings because the nc-WC/a-C:H one had no use in friction couple against aluminium alloys. Design/methodology/approach: In the paper the WC/a-C:H and (Si, Cr)C/a-C:H coatings were investigated. The coatings were investigated by means of SEM, EDS, in order to obtain thickness, surface morphology and chemical composition of coatings. Tribological properties of deposited coatings were elaborated by means of 'pin-on-disc' method in friction couple against 100Cr6 bearing steel and AlSi alloy. Findings: It was stated that (Si, Cr)C/a-C:H coatings have very good tribological properties in friction couple against bearing steel and AlSi alloy (friction coefficient <0,1). In case of WC/a-C:H coatings, good tribological properties were achieved in friction couple with bearing steel. Both coatings have very low wear rate in investigated friction couples. Research limitations/implications: The (Si,Cr)C/a-C:H coating have a worse quality of adhesion to quenched and tempered Vanadis 23 HS steel substrate in comparison with the nc-WC/a-C:H coating. Resolving this disadvantage can increase potential of application of (Si, Cr)C/a-C:H coatings. Practical implications: Newly developed (Si, Cr)C/a-C:H coating has a greater application potential for modification of surfaces of elements working in friction couples against hardened steels and light alloys like AlSi. Originality/value: There are numerous publications where low friction carbon based coatings were described mostly as a coatings deposited on elements working in friction couples against hard steels. Undertaken tests showed that the newly developed (Si,Cr)C/a- C:H coating can have a broad spectrum of applications in friction couples against different counterbodies, including light Al alloys.

Evaluation of corrosion resistance of electrodeposited nanocrystalline Ni–Fe alloy coatings

Nickel–iron alloys with a compositional range of 24–80 wt-% iron were electrodeposited on a copper substrate from a sulphate-based bath and using a stirring rate of 100 rev min−1. The effect of applied current density and Ni2+/Fe2+ metal ion ratio of plating bath on the properties of alloy coatings was examined. Crystal structure and grain size of Ni–Fe alloy coatings were investigated using X-ray diffraction technique. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy were used to analyse the surface morphology and chemical composition of coatings. Microhardness test was applied to evaluate the hardness of the coatings. Finally, the electrochemical behaviour of the Ni–Fe alloy coatings was studied by a polarisation test in 10 wt-% H2SO4 solution. Results revealed that current density and plating bath composition had a strong effect on the characteristics of coatings. As the iron content of alloys produced increased, their corrosion resistance improved with the best corrosion resistivity being achieved at a metal ion ratio of 0.5 and applied current density of 2.5 A dm−2.

Enhanced Photoelectrocatalytic Activity in Ni-TiO2 Nanocomposites Fabricated By Pulse Potential Deposition

The Ni-TiO2 single layer nanocomposites were fabricated on copper substrates by the pulse plating (PP) and pulse reverse plating (PRP) techniques. Morphological studies conducted by field emission scanning electron microscopy (FESEM) revealed that pulse potentials and durations affected the microstructure of coatings. The chemical composition of coatings was studied by energy dispersive X-ray system (EDX) and it was found that by the prolongation of current-off durations in PP and anodic cycles in PRP, deposits containing 11.58 wt.% and 13.16 wt.% TiO2 were produced, respectively. The influence of heat treatment temperature on the phase structure of Ni-TiO2 nanocomposites was investigated using X-ray diffraction and it was demonstrated that the anatase to rutile transformation occurred at temperatures higher than 450°C. The hydrophilicity of Ni-TiO2 coatings was evaluated by monitoring the change of water contact angle under the UV illumination. It was observed that the nanocomposite prepared by PRP exhibited the maximum hydrophilicity after 3 hours of heat treatment at 450°C, for which the contact angel prior to UV irradiation was 78.96° and after 1h of UV irradiation it reduced to 13.65°. Surface hydroxyl groups density which account for the photo-induced hydrophilicity of the Ni-TiO2 coating was defined by X-ray photoelectron spectroscopy (XPS), before and after 1h of UV illumination. The results indicated that under the optimized condition, for the coatings prepared by PP and PRP, 12.6% and 15.3% increases were detected in the density of hydroxyl groups. To evaluate the effect of pulse plating parameters on the photocatalytic activity of the Ni-TiO2 coatings prepared by PP and PRP, photo-degradation experiments of methyl orange aqueous solution were carried out under the UV light. The results indicated that TiO2 content, irradiation duration and sintering temperature affected the photocatalytic efficiency of the coatings, and the optimized PP and PRP deposited coatings were capable of disintegrating the methyl orange up to 76.21% and 51.89% after 1 hours of UV illumination. The photoelectrocatalytic degradation of methyl orange by Ni-TiO2 coatings was studied and the effect of different applied potentials was determined. The amounts of methyl orange degraded by the PP and PRP deposited composites under the anodic potential of 600 mV along with 1 hours of simultaneous UV illumination were 75.30% and 89.61%, respectively.

Cationic Redistribution at Epitaxial Interfaces in Superconducting Two-Dimensionally Doped Lanthanum Cuprate Films.

The exploration of interface effects in complex oxide heterostructures has led to the discovery of novel intriguing phenomena in recent years and has opened the path toward the precise tuning of material properties at the nanoscale. One recent example is space-charge superconductivity. Among the complex range of effects which may arise from phase interaction, a crucial role is played by cationic intermixing, which defines the final chemical composition of the interface. In this work, we performed a systematic study on the local cationic redistribution of two-dimensionally doped lanthanum cuprate films grown by oxide molecular beam epitaxy, in which single LaO layers in the epitaxial crystal structure were substituted by layers of differently sized and charged dopants (Ca, Sr, Ba, and Dy). In such a model system, in which the dopant undergoes an asymmetric redistribution across the interface, the evolution of the cationic concentration profile can be effectively tracked by means of atomically resolved imaging and spectroscopic methods. This allowed for the investigation of the impact of the dopant chemistry (ionic size and charge) and of the growth conditions (temperature) on the final superconducting and structural properties. A qualitative model for interface cationic intermixing, based on thermodynamic considerations, is proposed. This work highlights the key role which cationic redistribution may have in the definition of the final interface properties and represents a further step forward the realization of heterostructures with improved quality.

Impact of aluminum on the structure of geopolymers from the early stages to consolidated material

The aim of this study is to assess the effects of the addition of aluminum (NaAlO2) into the activating solution on the geopolymerization reactions and the characteristics of the porous network. It was established by liquid state NMR that the speciation of the aluminosilicate oligomers and then the mean degree of polymerization were modified by the addition of sodium aluminate in the activating solution. Time-resolved SAXS and rheology results on geopolymer pastes showed that the molar ratios Si/Al and (Si+Al)/Na2O in the activating solution play a major role in the geopolymer properties at liquid and solid state. Indeed, the geopolymer percolating network appeared sooner and the properties of the porous network were dramatically changed with the addition of the NaAlO2. On the other hand, two geopolymers having identical final chemical composition but a different activating solution composition, showed to the same setting time and the same porous network characteristics.

Internal Stresses in PVD Coated Tool Composites

AbstractThe aim of work is the investigation of the internal stresses in PVD coated metal matrix composites (MMC). Sintered MMC substrate is composed of the matrix with the chemical composition corresponding to the high-speed steel, reinforced with the TiC type hard carbide phase. Functionally graded composition of MMC providing of high ductility characteristic of steel in the core zone as well as high hardness characteristic of cemented carbides in the surface zone. Internal stresses were determined with use of finite element method in ANSYS environment. The reason of undertaking the work is necessity of develop the research of internal stresses, occurring in the coating, as well as in the adhesion zone of coating and substrate, which makes it possible to draw valuable conclusions concerning engineering process of the advisable structure and chemical composition of coatings. The investigations were carried out on cutting tool’s models containing defined zones differing in chemical composition.Modelled materials were characteristic of chemical composition corresponding to the high-speed steel at the core, reinforced with the TiC type hard carbide phase with the growing fraction of these phases in the outward direction from the core to the surface, additionally coated with (Ti,Al)N or Ti(C,N) functionally graded PVD coatings.Results of determined internal stresses were compared with the results calculated using experimental X-ray sin2ψ method. It was demonstrated, that the presented model meets the initial criteria, which gives ground to the assumption about its utility for determining the stresses in coatings as well as in functionally graded sintered materials. The results of computer simulations correlate with the experimental results.

Planetary nebulae in the Small Magellanic Cloud

We analyse the planetary nebulae (PNe) population of the Small Magellanic Cloud (SMC), based on evolutionary models of stars with metallicities in the range $10^{-3} \leq Z \leq 4\times 10^{-3}$ and mass $0.9 M\odot < M < 8M\odot$, evolved through the asymptotic giant branch (AGB) phase. The models used account for dust formation in the circumstellar envelope. To characterise the PNe sample of the SMC, we compare the observed abundances of the various species with the final chemical composition of the AGB models: this study allows us to identify the progenitors of the PNe observed, in terms of mass and chemical composition. According to our interpretation, most of the PNe descend from low-mass ($M < 2 M\odot$) stars, which become carbon rich, after experiencing repeated third dredge-up episodes, during the AGB phase. A fraction of the PNe showing the signature of advanced CNO processing are interpreted as the progeny of massive AGB stars, with mass above $\sim 6 M\odot$, undergoing strong hot bottom burning. The differences with the chemical composition of the PNe population of the Large Magellanic Cloud (LMC) is explained on the basis of the diverse star formation history and age-metallicity relation of the two galaxies. The implications of the present study for some still highly debated points regarding the AGB evolution are also commented.

Tenacidad a la fractura de compuestos cermets 3Al2O3*2SiO2/Ag manufacturados por molienda de alta energía

La fabricación de materiales compuestos de matriz cerámica reforzados con partículas metálicas han propiciado la formación de nuevos materiales conocidos como compuestos CERMETS, materiales que debido a sus elementos precursores poseen propiedades distintas a las de los materiales convencionales. En este trabajo se establece la ruta de fabricación de materiales compuestos cermets base 3Al2O3*2SiO2 reforzados con partículas metálicas de Ag a partir de la formación de la composición química en peso de polvos de 3Al2O3*2SiO2 / 1% Ag en busca de un aumento en la tenacidad a la fractura con respecto al cerámico base. La composición química de polvos es sometida a un proceso de mezcla molienda de alta energía en seco en un molino tipo planetario por 2 horas a 200 rpm. Los polvos posteriormente son conformados en muestras cilíndricas de 20 mm de diámetro y 3 mm de espesor mediante la aplicación de carga uniaxial en frío de 200 MPa. Las muestras son sinterizadas a 1500°C y 1600°C por una y dos horas en un horno de resistencia eléctrica en atmósfera controlada de gas nitrógeno. Los compuestos fabricados son analizados microestructuralmente por microscopia óptica y electrónica de barrido. Se determina la densidad y las propiedades mecánicas de dureza y tenacidad a la fractura, las dos últimas por el método de indentación. Los resultados muestran la viabilidad de fabricación de materiales compuestos cermets así como los cambios en la densidad, la dureza y la tenacidad a la fractura, con respecto al cerámico 3Al2O3*2SiO2 sin refuerzo metálico.

The Influence of the Chemical Composition of a Zinc Bath on the Growth Kinetics and Structure of Coatings Obtained on B500SP Steel

In the paper the results of tests conducted to determine the synergistic influence of alloy additions to a zinc bath upon the structure and growth kinetics of coatings obtained on reinforcing steel are presented. The structure and the chemical composition of coatings obtained on B500SP steel have been developed. The tests were carried out in Zn-AlNi, Zn-AlNiBi and Zn-AlNiBiSn baths. It has been determined that the additions of Bi and Sn reduce the coating thickness on B500SP reinforcing steel. The growth kinetics of coatings on the tested reinforcing steel - even though the concentration of Si was within the Sebisty range - did not show reversed temperature dependence, which is characteristic of this type of steel.

Partial least square with discriminant analysis and near infrared spectroscopy for evaluation of geographic and genotypic origin of arabica coffee

The agronomic practices and environmental conditions for coffee cultivation, such as climate, soil type and altitude, promote influence in the final chemical composition of the grain. Furthermore, the genotype directly influences the essential features of the beverage, increasing its aggregate price. Proof of geographic and genotypic origin of the coffee genotype must be done using reliable methods. Thus, near infrared spectroscopy (NIR) was used to analyze different coffee genotypes that were cultivated in Brazil. Due to complexity and quantity of information within the spectra, partial least square discriminant analysis (PLS-DA) were applied to analyze the NIR data. The multiplicative scatter correction (MSC) and the Savitzky–Golay second-derivative were tested as preprocessing techniques to find which one provides an appropriate identification model. The best model achieved correctly identified 94.4% of validation samples for both geographic and genotypic origin. The results demonstrate that NIR spectroscopy provides significant analytical data to be used in tandem with PLS-DA to distinguish green coffee samples geographically and genotypically.

Electrodeposition of black chromium–cobalt alloy based on trivalent sulfate electrolyte

This study is aimed to improve the corrosion resistance, adhesion strength, and color of trivalent black chromium coatings on steel substrates by using chromium sulfate bath and chromium chloride bath. The effects of the electrodeposition current density on the trivalent black chromium coatings were studied. Surface morphology and chemical composition of coatings have been investigated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. The protective behavior from substrates of trivalent black chromium coatings was studied in (3.5 wt. % NaCl) solution by potentiodynamic polarization technique. The better protective behavior from substrates was shown by coatings that formed in chromium sulfate bath. The coatings deposited at low current densities (10 A/dm2) showed high cobalt content because cobalt is more easily reduced than chromium on a cathode. The enhancement of the driving force caused chromium and cobalt to change into oxides and hydroxides when current density increased to more than 30 A/dm2. The best homogeneity of the black color, the degree of blackening and the protective behavior from substrates of coatings occurred at current density 50 A/dm2. The results of XPS indicated that the coatings contained not only chromium oxides and hydroxides but also cobalt oxides and hydroxides. Of all the constituent compounds, Co3O4 was the most dominant in influencing the degree of blackness.

The characterization of the coating formed by Microarc oxidation on binary Al–Mn alloys

In this study, effects of Mn content on behavior and properties of Microarc Oxidation (MAO) coatings produced on binary Al–Mn alloys and pure Al were investigated. Al–Mn alloys containing 1, 2, 4, 8 at.% Mn and pure aluminum produced using induction furnace under controlled atmosphere were coated in an alkaline electrolytic solution for 120 min. Surface roughness, thickness, microhardness, phase composition, microstructure and chemical composition of coatings were characterized by profilometry, Eddy Current test, microhardness measurement, XRD, SEM and SEM–EDS. All coatings composed of three regions: thin transition layer, dense inner region and porous loose outer region. Granular precipitates of α-Al2O3 were observed through dense inner region of coatings. With increasing Mn content, coating thickness increased from 111 μm to 169 μm. All coatings, regardless of substrate chemical composition, contained Al6Si2O13, γ-Al2O3, α-Al2O3 and considerable amount of amorphous phases. Increasing amount of Mn suppressed α-Al2O3 formation. It was seen that surface roughness and porosity formation tends to increase whereas the coating hardness tend to decrease with increasing Mn content. The coatings produced on Al–Mn alloys contained Mn along with Al, Si, O. The amount of Mn in the coatings increases with increase of Mn content in the substrates.

Redefinition of thalénite-(Y) and discreditation of fluorthalénite-(Y): A re-investigation of type material from the Österby pegmatite, Dalarna, Sweden, and from additional localities

AbstractUsing type material from the Österby pegmatite in Dalarna, Sweden, the chemical composition and structural parameters of thalénite-(Y) [ideally Y3Si3O10(OH)] were examined by wavelength dispersive spectroscopy electron microprobe (WDS EMP) analysis and single-crystal X-ray diffraction. High contrast back-scatter electron images of the Österby material show at least two generations of thalénite-(Y). The formula of the primary thalénite-(Y) normalized to 11 anions is (Y2.58Dy0.11Yb0.09Gd0.06Er0.06Ho0.02Sm0.02Tb0.02Lu0.02Nd0.01Tm0.01)Σ3.00Si3.01O10F0.97OH0.03. The secondary thalénite-(Y), replacing the primary material, is weakly enhanced in Y and depleted in the lightest and the heaviest rare-earth elements, yielding the formula (Y2.63Dy0.12Yb0.06Gd0.06Er0.05Ho0.02Sm0.02Tb0.02Tm0.01Nd0.01Lu0.01)Σ3.00Si3.01O10F0.98OH0.02. Structural data for thalénite-(Y) from Österby clearly indicate the monoclinic space group P21/n, with a = 7.3464(4), b = 11.1726(5), c = 10.4180(5) Å, β = 97.318(4)°, V = 848.13(7) Å3, Z = 4, which is consistent with previous investigations. The structure was refined from single-crystal X-ray diffraction data to R1 = 0.0371 for 1503 unique observed reflections, and the final chemical composition obtained from the refinement, (Y2.64Dy0.36)Σ3.00F0.987[Si3O10], Z = 4, is in good agreement with the empirical formula resulting from electron microprobe (EMP) analysis. Both techniques reveal a strong dominance of F over OH, which means that the type material actually corresponds to the fluorine analogue. Moreover, new EMP analyses of samples of thalénite-(Y) from an additional seven localities (Åskagen and Reunavare in Sweden; White Cloud and Snow Flake in Colorado, USA; the Guy Hazel claim in Arizona, USA; Suishoyama and Souri in Japan) clearly show the prevalence of F over OH as well. Based on these observations, the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association has recommended a redefinition of the chemical composition of thalénite-(Y) to represent the F-dominant species with the ideal formula Y3Si3O10F, as it has historical priority. Consequently, the later described fluorthalénite-(Y) has to be discredited.

Laser-induced changes in titanium by femtosecond, picosecond and millisecond laser ablation

In order to realize the qualitative control of the laser-induced changes trend and the quantitative control of the laser-induced changes range in titanium upon laser irradiation with different pulse duration, comparative ablation experiments by femtosecond, picosecond and millisecond pulsed lasers were carried out on titanium in this study. Then the final surface morphology, aspect ratio, chemical composition and microstructural state of the ablated titanium were analyzed by laser scanning confocal microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy, respectively. The dependency of the morphology, size, composition and microstructure of ablated titanium on laser pulse duration variation were emphatically discussed. It is found that, as the laser pulse duration increases from femtosecond to millisecond scale, surface morphology quality of ablated titanium gets worse, aspect ratio of microgroove decreases, proportion of titanium oxides in final ablation products becomes larger and the microstructural state of ablated titanium has a higher amorphization degree, which can be attributed to the decreased laser intensity per pulse and enhanced heat conduction effect in titanium with the pulse duration increasing.

Comparative study of the slurry erosion behavior of laser cladded Ni-WC coating modified by nanocrystalline WC and La2O3

The erosion performance of laser cladded Ni-60 %WC coatings subjected to a controllable abrasive water jet (AWJ) was investigated. The erosion resistance of Ni-60 %WC coatings at varied linear laser energy (from 315 to 700 J/mm) was examined under different impinging angles of a slurry jet. The chemical composition of coatings was modified by nanocrystalline WC powder and the rare earth element (La2O3). The erosion value of Ni-60 %WC was reduced to 40 % by decreasing the laser energy from 700 to 315 J/mm. Synthesized coatings with optimal weight fraction of nano-WC particles (5 %) and La2O3 (1 %) decreased the average microstructural grain size of the Ni-binder, increased the homogeneity and hardness of the coating, and consequently increased the erosion resistivity. The tribological evaluation of the erosion scars showed a log-linear relationship between coating hardness and volume loss under erosion. Adding nano-WC (5 %) and La2O3 (1 %) enhanced the bonding strength between Ni and WC and no pulled out WC particles was observed after erosion test.

Complex XRD and XRF Characterization of TiN-TiCN-TiC Surface Coatings for Medical Applications

Article presents results of measurements of vital parameters of PVD coatings of potential application in medicine (joint replacements or medical tools). The phase identification, level of residual stresses and texture were determined for various coatings by X-ray diffraction method. Chemical composition of coatings was verified by means of XRF. A set of measurements reveled the existence of advantageous compressive stresses in coatings, the texture determination showed undesirable fiber texture in TiN coating and advantageous uniformity of TiCN ones. XRF analysis pointed out the necessity of careful preparation of samples during PVD process during which phenomena of inhomogeneity in chemical can be present as it is presented in the paper.

The Effect of Al and Si Additions on the Resistance Properties of Magnetron-Deposited FeCrNi Coatings

The PVD magnetron sputtering method is one of the most efficient methods enabling the spraying of the multi-component materials and almost unlimited setting of the chemical composition of coatings. The micro-and nanocrystalline coating structure favours the selective diffusion of chromium and other alloy additions that form compact oxide layers. The paper presents the study of coatings made in the process of magnetron sputtering of AISI310S grade chromium-nickel steel. The study covered coatings of the steel's composition with additions of 2-5% Si and of 2-5% Al. The resistance of the coatings at temperatures induced by electric current flow was assessed. The coatings provided a resistance element in the electric circuit, and the measurementof their temperature was made by the voltage drop indirect method. It was found that the steel coatings had a resistance of 0.176 Ω within the entire range of testing temperature, and their failure occurred at a temperature of 350°C due to cracking and delamination from the substrate. Introducing the Si or Al addition to the coatings resulted in an increase in coating resistance and temperature stability, respectively, to 450 and 400°C. Changes of coating’s phase composition and texture were not found. The resistance of the coatings with the Al and Si additions decreased with temperature due to their oxidation.

THE INFLUENCE OF BRIQUETTED SYNTHETIC SLAGS ON STEEL REFINING IN LADLE

Synthetic slags are used during steel treatment in the ladle from the viewpoint of effective refinement. Their basic task is formation of active slag for improvement of kinetic conditions of refining processes. In the steel industry, a number of synthetic slags based on Al 2 O 3 are used which are produced from natural or secondary raw materials in different forms. However, the use of synthetic slags is influenced by the choice of used raw materials, by production technology and by final chemical composition. This paper shows plant results and experience with the utilization of briquetted synthetic slags based on Al 2 O 3 and containing different amount of Cr 2 O 3. Trial plant heats were realized during steel treatment under the conditions of steelwork VITKOVICE HEAVY MACHINERY a.s. The main aim of these heats was assessment of the plant results with utilization of two types of synthetic slags with different chromium content and the evaluation of the increase of chromium content in steel as well as the course of desulphurization during steel treatment.