Surface Modification Of Steel Research Articles

Reinforcing effect of surface-modified steel fibers in ultra-high-performance concrete under tension

The direct tensile behavior of ultra-high-performance surface-modified steel fiber-reinforced concrete was evaluated in this study. Various chemical modifications were applied to steel fibers, including acetone washing, hydrochloric acid washing, zinc phosphating, silica coating, and chelation using an ethylenediaminetetraacetic acid (EDTA) electrolyte solution, which improved the tensile strength, tensile strain, and g-value to a maximum of 17.76 MPa, 1.22%, and 144.51 kJ/m3, respectively. Acetone washing and EDTA chelating were the most effective methods for improving the tensile strength, whereas silica coating was the best for improving the strain capacity and energy absorption capacity. The optimal treatment time for EDTA chelation treatment was approximately 6 h, and the tensile performance decreased considerably after 12 h of treatment. Comparing these results with those of pullout experiments revealed that a high shear stress should be maintained after the fiber has fully debonded to effectively enhance the post-cracking tensile performance.

Modification of steel surfaces with aluminum oxide particles: study of wetting and spreading

This work presents the experimental studies on the influence of the average particle size of aluminum oxide used to modify stainless steel surfaces on the change in wetting properties and the movement of the three-phase contact line. To record the formation of a droplet on the surface, we used the equipment of the shadow technique. he geometrical dimensions of the droplets were determined by the Young-Laplace, Tangential 1 and 2 methods. It was found that the larger the average size of aluminum particles used to modify steel surfaces, the more wetting properties and the characteristics of liquid spreading over such surfaces will change.

Duplex surface modification of tool steel - deposition of a WN film and subsequent electron-beam modification

In this study, we demonstrate a combined treatment technique of R18 high-speed tool steel comprising deposition of a WN coating followed by electron-beam surface treatment (EBT). In order to understand the influence of the deposited WN coating on the resultant structure and properties, an uncoated specimen was directly electron-beam treated under the same EBT technological conditions. The structure of the specimens was studied by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The microhardness was also investigated. The phase composition consisted of a double phase structure of Fe and M6C carbides in both cases. The microstructure was significantly finer in the case of an EBT of the steel with WN coating, leading to a much higher microhardness in comparison with the case without WN.

Microstructures and fatigue behaviors of 25CrNi2MoV steel under electropulsing-assisted ultrasonic surface rolling

In this paper, the surface modification of 25CrNi2MoV steel was carried out by using electropulsing-assisted ultrasonic surface rolling (EUSR) process. Nano-gradient structures were prepared on the surface and subsurface of the material. The surface roughness was remarkably reduced. The surface hardness, the surface residual compressive stress and the fatigue resistance of the shaft steel are improved by EUSR treatment. The effect of EUSR treatment on the surface properties and fatigue properties of 25CrNi2MoV steel was systematically studied. The fatigue crack growth mechanism of the specimens after EUSR treatment was mainly discussed. It was concluded that the depth of the hardened and residual stress layers was significantly increased by the EUSR treatment. The fatigue life of the specimens was obviously increased by EUSR treatment. The misorientation of adjacent grains is an important indicator that affects fatigue crack growth.

Pravci razvoja i primene plazma nitriranja u industriji

This paper presents a discussion of the results of previous research of the effects of surface modification of structural materials and tool steels using plasma nitriding (PN) in order to improve their mechanical, tribological and corrosion behavior. The paper discusses the current status and future directions in the application of PN on various wearing components that are exposed to high loads, stresses and frequent temperature changes. The paper provides an overview of the relevant literature whose results show the most favorable or optimal parameters of the PN process aimed at achieving the best performance in terms of wear and corrosion resistance and hardness increase for the various materials considered. Systematization of literature data about research of the impact of low-temperature PN on stainless steels has placed emphasis on those process mechanisms that achieve benefits for surface layers without creating negative side effects in the form of loss of corrosion resistance. The strengthening of hot forging dies is considered through the reasons and problems that cause the need for the application of PN, and then paper focuses on the role of PN in achieving the tribological properties required to extend the service life of the die. Publications in which the nitriding of titanium alloys is investigated through the reduction of wear, increase of bearing capacity and microhardness depending on the input parameters of the process, ie the optimal parameters applied in order to obtain the best performance characteristics are cited. The application of PN to aluminum and its alloys is discussed, as well as the conditions of testing and the achieved improvements.

Probabilistic optimization of machining of duplex stainless steel in electric discharge machining with hydroxyapatite nanoparticles mixed dielectric medium

The electric discharge machining has been carried out in the current study for the surface modification of Duplex Stainless Steel (DSS 2205). The machining process is carried out in the hydroxyapatite nanoparticles (Ca5(OH)(PO4)3)(HAP powder) mixed dielectric medium with a copper tungsten electrode in reverse polarity. To determine the optimal machining parameters, the Taguchi L18 orthogonal array approach was employed, and the input machining variables in terms of discharge current, voltage, pulse-on time and pulse-off time were chosen. It has been observed from the results that the discharge current contributing 58.18%, pulse-off time contributing 16.77% and pulse-on time contributing 15.83% were the most significant factors in improving the MRR. The optimum machining parameters for achieving the maximum MRR (0.305 mg/min) with EDM Oil were recognized at discharge current of 16 Amp, pulse-on time of 200 μs, pulse-off time of 60 μs and the applied voltage of 80 V and with nano powder mixed electric discharge machining, the maximum MRR (0.271 mg/min) were observed at discharge current of 16 Amp, pulse on time of 150 μs, pulse off time of 60 μs and voltage 80 V. MRR is reduced by 11% when NPMEDM is used. XRD analysis confirms the modification on the surface of nano powder mixed electric discharge machining demonstrating the formation of several intermetallic compounds.

Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or γN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

Surface modification of SPK NL steel: relevance to tribological and electrochemical potency

SPK NL steel, as a hard and process-wise stable alloy, has myriad applications in sheet metal forming. However, to increase the quality of the products and decrease cost, applying a self-lubricant protective coating on the surface seems to be an efficacious strategy. The CrN and carbon-enriched CrN, i.e. (a-C: CrN), hybrid coatings are physically vapor-deposited on the SPK NL alloy surface. The C/N ratio on the morphology, tribological properties, mechanical characteristics, and anticorrosive features of the coated SPK NL substrates are studied. Results evidenced that high carbon inclusion increases the plastic hardness of the CrN coating up to about 35 GPa and significantly improves the plasticity index to ~0.2. The COF decreases from ~0.6 for CrN to ~0.1 for a-C:CrN. Coatings with a high sp2 fraction impart an excellent self-lubricant characteristic to SPK NL steel. Electrochemical impedance spectroscopy data approve that both coatings provide high corrosion resistance, and although CrN provides superior corrosion resistance nonetheless. As an outcome, (a-C: CrN) hybrid coatings with high carbon content, possessing high hardness, good tribological properties, and corrosion resistance seems to be a prospective candidate for surface protection of SPK NL steel.

Investigation of Surface Modification of 60CrMoV18-5 Steel by EDM with Cu-ZrO2 Powder Metallurgy Green Compact Electrode

Electrical discharge machining (EDM) is a non-conventional machining process, which is mostly used for machining of difficult-to-cut materials. These materials are often used in engineering applications that require improved surface properties; thus, surface modification is desirable in these cases. In the recent past, it has been observed that EDM is an alternative surface modification process due to migration of material from the electrode to the workpiece surface. Surface modification can be done with powder metallurgy (P/M) electrode as tool. The aim of this work is to examine the surface modification of the tool steel Calmax (Uddeholm) by EDM process using Cu-30 wt.% ZrO2 P/M green compact electrode. The influence of peak current (Ip) and pulse-on (Ton) on the Material Transfer Rate (MTR) and Surface Roughness (SR) was investigated and the surface characteristics were also evaluated by scanning electron microscopy (SEM). The experimental results confirm the material migration from the electrode to the machined surface and show that the higher MTR of 46.5 mgr/min is achieved on the combination of Ip = 9 A and Ton = 25 μs and the Ra varies from 3.72 μm to 7.12 μm.

Ytterbium impulse laser for surface modification of tool steel with B4C-Al powders

The paper deals with a new application solution of Ytterbium Picosecond Pulsed Fiber Laser for surface modification of 3Kh2V8F hot-work tool steel (the analog of AISI H21 steel). Surface modification was conducted by B4C-Al powders from preplaced pastes followed by laser heating. The ratio of B4C-Al powders was taken as 5/1 by weight and the paste thickness was approximately 1 mm. Laser treatment was conducted according to the following parameters: 1070 nm of wavelength, 100 W of power, 1 mJ of pulse energy, 100 ns pulse duration, pulse frequency range from 50 kHz to 90 kHz. Several tracks with different widths were obtained as a result of treatment depending on velocity of the laser move. EDS analysis showed that B4C particles were not completely dissolved in the weld beads. However, an enhanced concentration of boron (8-12 wt.%) was revealed in the vicinity of B4C particles. The aluminum concentration was low (up to 0.79 wt.%) on the surface of the weld beads.

Thermodynamic aspects of electron-beam surface modification of low-carbon steel

Multicomponent surface modification of carbon steels is of high interest in mechanical engineering due to its beneficial impact on machine components’ and structures’ surface properties. The present research was devoted to simulating the process of aluminides and borides formation on the surface of low-carbon steel during electron beam alloying and predict the phase composition of the obtained coatings. Computational thermodynamics and approximate calculation method were used to solve the problem mentioned above. Calculations were done in the temperature range between 200 and 2000 K at 10−3 Pa. It was discovered that the calculated and experimental data of the coating’s phase composition differs significantly. The only confirmed phase that was predicted by the calculations was sodium fluoride (NaF). It was established that NaF presence in the treatment paste was redundant for the electron beam alloying because of its low reactivity in a vacuum. XRD analysis revealed the following phases in the coating: Fe2B, Fe3C, and AlFe3.

Comparing chemical and plasma modification of stainless steel surfaces – Relevance for adsorption of adhesion promotor vinyltrimethoxysilane (VTMS)

Coated stainless steel surfaces with silane compound coupling agent are implemented in many industrial applications. For vinyltrimethoxysilane (VTMS) adsorption optimization, surface modification of stainless steel type V2A was performed with plasma, ozone and in sodium hydroxide (NaOH) solutions. Subsequent a systematic study of a central composite design of experiments (DoE) accomplished with X–ray photoelectron spectroscopy (XPS) data. Similar results in ozone, oxygen (O2)–, and water (H2O)–plasma treatment led to a detailed presentation of the results from the O2–plasma and NaOH treatment. Treatment effects on the surface roughness were determined using atomic force microscopy (AFM) and the functional groups of VTMS on the surface with surface enhanced Raman spectroscopy (SERS). All treatments resulted to a reduction of C and a higher oxidized surface whereas the Fe/Cr–ratio and OH-content were changing significantly after NaOH treatment. Only the root mean squared (RMS)–values calculated from the AFM images of NaOH treated V2A samples indicated an increased coverage of VTMS after longer treatment time in higher concentrated NaOH solutions. The results of this study enable setting the amount of VTMS bonding to the surface of V2A due to NaOH pretreatment.

Modification of Steel Surfaces with Nanometer Films of Al2O3 and TiO2 Decreases Interfacial Adhesion to Polymers: Implications for Demolding Shape-Engineered Polymer Products

Alumina (Al2O3) and titanium dioxide (TiO2) thin films were deposited by the atomic layer deposition technique on steel substrates used in the polymer injection molding industry. The modified steel surfaces were systematically characterized by SEM, EDS, AFM, XPS, and OCA. Surface energy values were obtained to predict the demolding behavior of modified steel surfaces when in contact with different polymers. The lowest surface energy was obtained using Al2O3 and H2O as an oxygen source on 1.2311 steel (1.2311-Al-H), representing a 30% decrease when compared to 1.2311 bare ground steel. Results were confirmed by the simulation of polymer–mold interaction. The produced polycarbonate surface presents defects with an average diameter of 0.5 μm that result from mimicking of the Al2O3 textured surface (contrasting with the defects with a diameter of 1.85 μm using bare 1.2311 steel). The best compromise between surface energy and roughness was obtained using the TiO2-H2O film (1.2311-Ti-H). The modified steel with TiO2 ALD coating produced the smoothest polymeric surface. The modification of steel surfaces with nanometer films of Al2O3 and TiO2 decreased the interfacial adhesion to polymers, which had implications for demolding shape-engineered polymers, a requirement for high-aspect-ratio parts.

Surface modification and its effect on the tensile and fatigue properties of 300M steel subjected to ultrasonic surface rolling process

Surface modification of 300M steel induced by ultrasonic surface rolling process (USRP) was studied regarding surface topography , microstructure, the distribution of shear strain, microhardness , and residual stress profiles. The effects of USRP on the tensile and fatigue properties were finally discussed. The results indicated that one pass of USRP can reduce the surface roughness ( R a ) by more than one order of magnitude (from 0.30 μm to 0.025 μm). Besides, a severe plastic deformation layer was noticed at the top surface, which led to an increase of surface microhardness by about 17% and an elevation of compressive residual stress by about 190%. In USRP, a high plastic shear strain of ~3 and shear strain rate of ~10 5 s −1 can be induced into the topmost surface, which motivates the dislocation activities in the form of dislocation tangles, dislocation walls, and dislocation cells. Dislocation slip supplemented by mechanical twinning dominates the microstructural evolution pattern of the USRP sample. The excellent surface finish, high microhardness, and high compressive residual stress result in an obvious increase in the resistance of high-cycle fatigue behavior. Besides, the tensile strength was improved by 3.8%, whereas the corresponding yield strength and elongation were reduced by 5.9% and 24.3%, respectively. • Only one-pass USRP can reduce the surface roughness by more than one order of magnitude. • A high plastic shear strain of ~3 and strain rate of ~10 5 s −1 appears on the topmost surface after USRP. • Dislocation slip assisted by the mechanical twinning dominates the microstructural evolution pattern. • An obvious increase in the resistance of high-cycle fatigue is obtained after USRP.

In situ surface modification of stainless steel with hydroxyapatite using microwave heating

The present work involves enhancing the biocompatibility of austenitic stainless steel (SS-316L) implants by changing its surface composition and morphology through the microwave hybrid heating (MHH) technique. The polished SS-316L alloy surface layer was modified with bioactive hydroxyapatite (HAP) powder by utilizing an Industrial microwave oven operated at 2.45 GHz and 1.1 kW. The modified layer of SS-316L alloy was characterized in terms of phase analysis, microstructure investigation, porosity analysis and apatite forming ability. The microstructural investigation revealed that the presence of austenite dendrites with HAP along with some reaction induced phases like Fe3P, FeP, and Fe2P mainly in the inter-dendritic regions of the modified layer of SS-316L alloy. The microhardness of modified layer was higher than that of the unmodified layer of SS-316L alloy. The modified layer exhibited porosity in the range of 2% to 3%. The in-vitro study performed in simulated body fluid (SBF) solution indicates that the microwave-assisted surface modified layer of SS-316L alloy exhibited an improved bioactivity. The SEM images indicate the formation of apatite layer in the modified layer of SS-316L alloy. The observed biological improvements in the microwave-assisted modified layer was due to the cladding induced changes in the surface morphology and surface chemistry of the SS-316L substrate material.

Surface modification of AISI-304 steel by ZnO synthesis using cathodic cage plasma deposition

Zinc-oxide (ZnO), a solid lubricant coating, can increase the wear resistance of steels by working as a self-lubricant. In this study, ZnO film is synthesized using the cathodic cage plasma deposition (CCPD) technique, using galvanized steel cathodic cage (steel cage with zinc coating). The effect of gas composition (H2 is added in Ar-O2) is investigated to optimize the film properties. The surface hardness is increased more than twice in each processing condition. The deposited film shows ZnO phases for samples treated with low hydrogen contents and a combination of ZnO and magnetite phase (Fe3O4) with higher hydrogen contents. The thickness of film reduced from 1.28 μm to 0.5 μm by increasing the hydrogen composition. The wear resistance is expressively increased by film deposition, and the abrasive wear mechanism is changed to an adhesive wear mechanism. A significant decrease in wear rate is observed, specifically by increasing the hydrogen contents. The friction coefficient as a function of sliding distance is smoother and lower than the base material in each condition. This study suggests that the CCPD technique can effectively deposit the solid lubricant coating of ZnO, and it can be used to enhance the tribological properties of steel samples. Moreover, this technique is convenient due to its better deposition efficiency, eco-friendly (no chemicals are involved), simple and relatively low-cost equipment, and low processing temperature. Thus, it can be advantageous for industrial sectors interested in materials with exceptional tribological properties.

Surface modification of carbon steel by electrodeposit composite coating for improving erosion-corrosion resistance: a review

This paper included an explanation of one of the methods of protection from corrosion, as it dealt with the use of electroplating technology by using solid ceramic particles embedded in chromium on carbon steel as a base material as an effective way to increase the service life of fluid-carrying tubes, considering that they are exposed to a joint effect of chemical and physical action. The formation of composite coatings on carbon steel and the factors affecting the success of these coatings in addition to a group of studies that dealt with these factors and their impact on increasing the resistance to conditions surrounding the metal represented by resistance to chemical corrosion in the presence of erosion (such as the concentration of solid particles in the paint solution, the temperature of the paint solution, the effect of The current density on the quality of the coatings and the effect of the thermal treatment on the coatings). The current density, the concentration of solid particles and the temperature have the greatest influence in determining the efficiency of the composite coatings.

Improved Biological Responses of Titanium Coating Using Laser-Aided Direct Metal Fabrication on SUS316L Stainless Steel.

Direct metal fabrication (DMF) coatings have the advantage of a more uniform porous structure and superior mechanical properties compared to coatings provided by other methods. We applied pure titanium metal powders to SUS316L stainless steel using laser-aided DMF coating technology with 3D printing. The purpose of this study was to determine the efficacy of this surface modification of stainless steel. The capacity of cells to adhere to DMF-coated SUS316L stainless steel was compared with machined SUS316L stainless steel in vitro and in vivo. Morphological in vitro response to human osteoblast cell lines was evaluated using scanning electron microscopy. Separate specimens were inserted into the medulla of distal femurs of rabbits for in vivo study. The distal femurs were harvested after 3 months, and were then subjected to push-out test and histomorphometrical analyses. The DMF group exhibited a distinct surface chemical composition, showing higher peaks of titanium compared to the machined stainless steel. The surface of the DMF group had a more distinct porous structure, which showed more extensive coverage with lamellipodia from osteoblasts than the machined surface. In the in vivo test, the DMF group showed better results than the machined group in the push-out test (3.39 vs. 1.35 MPa, respectively, p = 0.001). In the histomorphometric analyses, the mean bone-to-implant contact percentage of the DMF group was about 1.5 times greater than that of the machined group (65.4 ± 7.1% vs. 41.9 ± 5.6%, respectively; p < 0.001). The porous titanium coating on SUS316L stainless steel produced using DMF with 3D printing showed better surface characteristics and biomechanical properties than the machined SUS316L.

Inhibitory effect of L-Threonine and L-Lysine and influence of surfactant on stainless steel corrosion in artificial body solution

Stainless steel 316L is a biomaterial, widely used in medicine for the fabrication of implants in orthopedics and cardiovascular surgery. The human body is an extremely aggressive environment and materials used for implants need to be highly resistant to corrosion and degradation. Corrosion of steel leads to the release of ions which are toxic to humans and may cause inflammatory processes in the body. Therefore, it is very important to decrease corrosion of stainless steel implants and to find inhibitors that will not cause health effects and that can be safely used. Amino acids are biomolecules that have confirmed action as corrosion inhibitors in aggressive solutions. The aim of this study is to investigate the inhibition action of rarely studied amino acids, L-Lysine and L-Threonine, on the corrosion process of stainless steel in artificial body solution using open circuit potential measurements, potentiodynamic measurements, electrochemical impedance spectroscopy measurements, surface scanning by atomic force microscopy (AFM) and quantum chemical calculation during the investigation. In order to increase the inhibition efficiency, sodium dodecyl sulphate (SDS) was used as an agent for modification of stainless steel surface that provides effortless adsorption of L-Lysine molecules on the electrode surface. Results obtained by potentiodynamic polarization measurements reveal that L-Lysine and L-Threonine act like mixed-type inhibitors with a more pronounced influence on cathodic processes. Also, potentiodynamic curves indicate that L-Lysine and L-Threonine act through adsorption onto the steel surface without changing the mechanism of corrosion of steel. Adsorption follows the Langmuir adsorption isotherm. EIS measurements reveal that charge transfer resistance increases in the presence of amino acids and after pretreatment in SDS solution indicating an increase of protection ability of formed film on the stainless steel surface. Results achieved by AFM reveal that the steel surface becomes smoother in BM − 3 solution with the addition of L-Lysine, suggesting adsorption of the amino acid molecule on the electrode surface. AFM results also indicate that SDS facilitates adsorption of amino acid molecules onto the steel surface. DFT results provide theoretical support for the results obtained by electrochemical studies. Taken together, experimental and theoretical results reveal that tested amino acids can be used as corrosion inhibitors in artificial body solution.

Protection of steel constructions against wear and corrosion in difficult climatic conditions by new techniques of zinc metallization

In the paper modernized techniques of zinc metallization of steel in combination with nitriding are considered. Two methods of combined surface modification of low-carbon steel are studied: application of zinc coatings by painting technique and subsequent gas nitriding; simultaneous thermo-diffusion saturation by zinc and nitrogen. Microstructure and microhardness of steel samples were examined; forming of a transition zone was determined under visually observed surface layer/coating with increased concentrations of Zn and N. Combined saturation by zinc and nitrogen forms diffusion layers with increased wear resistance and reduced friction coefficients together with improved corrosion resistance in salt fog. Nitriding of Zn coatings protects the steel both in salt and acid mediums.