Surface Modification Of Steel Research Articles

Surface Modification of Low Carbon Steel by Using Electrophoretic Deposition Technique with Graphene Oxide Powder

In this research, low carbon steel surface was modified using electrophoretic deposition (EPD) technique from a graphene oxide (GO) water suspension. The electrophoretic deposition (EPD) is the technique used for manipulation and deposition of nanomaterials. The GO coating was used as a layer to increase the hardness of low carbon steel. GO was successfully synthesized using the modified Hummers method. EPD technique was performed by applying voltage at 9 volts and the deposition time of 15 mins. The working distance between the cathode and anode was fixed at 15 mm. The GO film had been deposited by EPD technique where it was carburized at 900, 950, 1000 and 1050°C, for 60 mins. The microstructure of the carbide film was investigated using scanning electron microscopy (SEM). As the carburization temperature raised (1050°C), more volume carbon atoms reacted with iron atoms to form iron carbon (Fe3C) layer on to the substrate surface. The carbide films are columnar crystal growth with a particle size of approximately 50 μm. The growth rate of the carbide films at 1050°C is about 8 µm/min. Energy dispersive X-ray spectrometer (EDS) was studied for chemical elements analysis. Fe, C and O elements were then detected. At carburization temperature of 1050°C, it showed that C element distribution is higher than others’ temperatures. Moreover, the hardness on the carbide films was investigated using a Vickers hardness tester under an applied load of 500 grams for 10 seconds. It was found that the hardness increased with the increasing carburization temperatures. The hardness of low carbon steel is 172.99 ± 2.28 HV. After the carburization processing via GO at temperature of 1050°C, the highest hardness of 821.42 ± 35.33 HV was obtained. It was observed that the mechanical properties of low carbon steel surface were found to be strongly influenced by the process of carburization temperature.

Steel Surface Modification by Cathodic Carburising and Anodic Polishing in Electrolysis Plasma

Steel Surface Modification by Cathodic Carburising and Anodic Polishing in Electrolysis Plasma

Properties of a Plasma-Nitrided Coating and a CrNx Coating on the Stainless Steel Bipolar Plate of PEMFC

PEMFC are considered to be the most promising for automotive energy because of their good working effect, low temperature, high efficiency, and zero pollution. Stainless steel as a PEMFC bipolar plate has unparalleled advantages in strength, cost, and processability, but it is easy to corrode in a PEMFC working environment. In order to improve the corrosion resistance, the surface modification of 316L stainless steel is a feasible solution for PEMFC bipolar plates. In the present study, the plasma-nitrided coating and CrNx coating were prepared by the plasma-enhanced balanced magnetron sputtering technology on the 316L stainless steel surface. The microstructures, phase compositions, and corrosion resistance behavior of the coatings were investigated. The corrosion behavior of the prepared plasma-nitrided coating and CrNx coating was investigated by potentiodynamic polarization, potentiostatic polarization, and electrochemical impedance spectroscopy (EIS) in both cathodic and anodic environments. The experimental results show that corrosion resistance of the CrNx coating was better than the plasma-nitrided coating. It was indicated that the technology process of nitriding first and then depositing Cr was better than nitriding only.

Effect of surface modification of electrodes on charge injection and dielectric characteristics of propylene carbonate

Space charge injected into a liquid dielectric by an electrode under an impulse voltage causes the electric field to be distorted, which affects the dielectric's insulation performance. In this study, the authors study the surface modification of three-electrode materials, namely aluminium, copper, and stainless steel, by sputtering of titanium dioxide (TiO2) based on magnetron sputtering. The breakdown voltage of propylene carbonate and the surface morphology of the electrodes before and after modification were examined. Furthermore, the distribution of the space charge injected into the propylene carbonate from the different electrode materials was also measured based on the Kerr electro-optic effect. These results indicate that the breakdown voltage of propylene carbonate increased by 7, 4, and 9% after surface modification of aluminium, copper, and stainless steel, respectively. After sputtering of TiO2, micro-grooves on the surface of the three-electrode materials became smooth, and the surface roughness decreased, which changed the barrier height of the solid–liquid interface. The space charge injection mode of the three-electrode materials before and after surface modification was bipolar injection; however, the space charge injection amounts were markedly lower for the modified electrodes.

Surface modification of M2 steel by combination of cathodic cage plasma deposition and magnetron sputtered MoS2-TiN multilayer coatings

Titanium nitride (TiN) is a good choice for the improvement in surface hardness of high-speed steel. Unfortunately, it has low adhesion with substrate and exhibits high friction coefficient; as a result it does not provide sufficient protection against sliding wear in metal-to-metal contact. The adhesion problem can be removed by nitriding process, whereas friction coefficient can be reduced by solid lubrication coating. In this study, an attempt is made to synthesize TiN hard coating as well as solid lubrication coating of molybdenum disulfide (MoS2) using magnetron sputtering, along with substrate pre-treatment by cathodic cage plasma deposition using titanium cathodic cage. The cathodic cage plasma nitrided sample exhibits significantly higher surface hardness, which reduced by solid lubrication coating. The nitrided sample depicts the presence of iron nitrides, TiN and nitrogen diffused martensite phases, whereas coated samples shows the presence of MoS2 and TiN phases. The friction coefficient and machining temperature are dramatically reduced by lubrication coating. This study recommends that the use of cathodic cage plasma nitriding using titanium cathodic cage is beneficial for improved surface hardness, and addition of solid lubrication coating is beneficial for reducing the coefficient of friction and machining temperature by scarifying hardness. As, both the systems are already proven to be appropriate for industrial-scale uses, thus results from this study can be applied for industrial-scale application.

ОСОБЕННОСТИ МОДИФИКАЦИИ ПОВЕРХНОСТИ ИНСТРУМЕНТАЛЬНЫХ СТАЛЕЙ ЛАЗЕРНЫМ ИЗЛУЧЕНИЕМ

ОСОБЕННОСТИ МОДИФИКАЦИИ ПОВЕРХНОСТИ ИНСТРУМЕНТАЛЬНЫХ СТАЛЕЙ ЛАЗЕРНЫМ ИЗЛУЧЕНИЕМ

Study on the Selective Surface Modification of Injection Mold Steels by Laser Materials Processing: Relationship Between AlN Formation and Surface Hardening During Laser Nitriding

Laser surface heat treatment and laser nitriding processes were applied using selective surface modification techniques to investigate phase transformation, microstructural evolution, and surface hardening behaviors for two types of plastic injection mold steels, AISI 1045 and P21. During laser surface heat treatment, a 245% hardness increase compared to that of the base metal (290 HV) was achieved due to martensite transformation of the AISI 1045 steel. However, for the AISI P21 steel, hardness within the heat-treated zone was largely unchanged from that of the base metal (410 HV) despite being accompanied by martensite transformation. Compared to that of the base metal, this static hardness behavior of the heat treated P21 steel was due to coarsening of Cu particles induced by the laser irradiation. To overcome the static hardness behavior of P21 steel, laser nitriding was used. The laser-nitrided specimen (at 4500 J/mm heat input) was approximately 40% (577 HV) harder than the base metal (410 HV) and was highly correlated with nitride formation. Nitrogen successfully penetrated the surface of the specimen during laser irradiation and formed a nitrided layer mainly composed of an AlN phase. Thus, the surface hardening behavior of AISI P21 steel after laser nitriding could be largely attributed to the AlN phase development. Key words: plastic injection mold steels, surface modification, laser surface heat treatment, laser nitriding, nitride

Simple and fast surface modification of nanosecond-pulse laser-textured stainless steel for robust superhydrophobic surfaces

Superhydrophobic surfaces have been extensively studied for their unique low water adhesion. However, surface robustness and manufacturing difficulties are barriers to widespread use of superhydrophobic surfaces. In this study, a simple and fast surface modification of short-pulse laser-textured surface is developed for a robust superhydrophobic surface. Normally, short-pulse laser-textured surfaces can become superhydrophobic, but require toxic chemical coating, prolonged aging in air, or heat treatment for several hours. In our method, with only 10 minutes of heat treatment with non-toxic silicone oil, the nanosecond-pulse laser-textured stainless steel surface becomes superhydrophobic and shows good robustness.

Surface modification of mild steel before acrylic resin coating by hybrid ZnO/GO nanostructures to improve the corrosion protection

The synergistic effect of ZnO and GO nanostructures on the surface modification of mild steel before the acrylic resin coating was studied. Firstly, the steel surface was pretreated in the presence of ultrasonic irradiation, and then ZnO nanostructures were synthesized by the cyclic voltammetry technique. GO nanosheets prepared by the modified hummer’s method were deposited on ZnO-containing surfaces using the electrophoretic deposition (EPD) technique. GO coatings with thicknesses of 2.84, 4.47 and 9.42μm were obtained by varying the EPD time, and the 4.47μm was found as the optimum value for the fabrication of hybrid ZnO/GO structures. All samples were then covered with a thin layer of acrylic resin (10μm) by the spin coating technique. The results indicated that the sample with underneath of hybrid ZnO/GO nanostructures shows significant improvement in anti-corrosion performance. In other words, Rp is increased from 150,000Ωcm2 (in the rein coated sample) to 380,000Ωcm2 (in the sample with hybrid nanostructures). The resulting surface has the potential to use as protective and glossy black coatings. The role of underneath nature, surface roughness, and molecular interactions between oxygen functional groups of ZnO, GO, resin, and the metal in the enhanced corrosion protection was illustrated.

Surface Modification of Steel by Anodic Plasma Electrolytic Boronitriding and Polishing

The paper shows the possibility of plasma electrolytic polishing of the steel surface after its chemical-thermal treatment. Positive results of the plasma electrolytic polishing are obtained for low carbon steel after its anodic plasma electrolytic boronitriding. An X-ray diffractometer and a scanning electron microscopy were used to characterize the phase composition of the modified layer and its surface morphology. Surface roughness was studied with the use of a roughness tester. The hardness of the treated and untreated samples was measured using a microhardness tester. Corrosion properties of the samples treated surfaces were evaluated using potentiodynamic polarisation tests in solution of sodium chloride. The reduction of the surface roughness of 1.7 times and the corrosion current density of 1.5 times of boronitrided steel by plasma polishing using mode of current interruption for 2 min without changing the structure of the diffusion layers is shows.

Effect of Nitriding on the Microstructure and Mechanical Properties of Stainless Steels

Austenitic stainless steels are common spread in many industries. Plasma nitriding is one of the few technologies that allows surface modification of austenitic stainless steels. In this study, a plasma nitriding method to form a hard surface layer at two different austenitic steels AISI 302 and AISI 316L. The surface morphology, chemical composition and mechanical properties of the formed layers were described and the results were compared with each other. The formed nitrided layers on both steels created a uniform multi-phase layer which was characterized by high hardness and very good abrasion resistance.

Surface modification of steel 20 by the method of chemical-thermal treatment by annealing in a muffle furnace

The article is devoted to the current problem related to the hardening of the surface layers of metal materials, including steel parts. The authors of the article describe the methods of chemical and thermal treatment of surface layers of materials to effectively improve the durability of machine parts and tools operating under various conditions of wear, at high temperature and force effects. The method of saturation of samples of iron plates by means of coating them with boron-containing mixtures in different volume proportions and their subsequent annealing in a muffle furnace is considered. The results of studies of the microhardness and thickness of the diffusion layer are given.

Ultrasonic nanocrystal surface modification of high-speed tool steel (AISI M4) layered via direct energy deposition

Abstract Tensile residual stress in the laser-deposited M4 fabricated by direct energy deposition (DED) may reduce the fatigue performance and tool life. Ultrasonic nanocrystal surface modification (UNSM) can induce compressive residual stress by generating severe plastic deformation of the material surface, and improve the wear resistance through surface texture refinement. In the present study, we investigated the changes in the metallurgical and mechanical properties of DEDed M4 specimens as induced by UNSM treatment. An X-ray diffraction analysis showed that the DEDed M4 austenite was transformed into martensite after UNSM processing. The change in the full width at half maximum revealed a grain size decrease of 25.8%. Conversion of the tensile residual stress within the DEDed M4 to compressive residual stress through UNSM treatment was confirmed. These changes in the metallurgical characteristics yield a 24.1% increase in the DEDed M4 hardness. A wear test was conducted to evaluate the wear resistances of heat-treated D2, DEDed M4 on D2, and UNSM-DEDed specimens. Ball-on-disk wear tests revealed that the DEDed M4 specimen wear rate was 68.3% lower than that of the H-D2. In addition, the DEDed M4 wear rate was reduced by 85.7% through UNSM treatment. The surface roughness was reduced by up to 88.3%, while micro-dimple shapes were formed on the DED-treated M4 surface. This study has demonstrated that UNSM can be applied to a DED-treated M4 surface to enhance its metallic and mechanical properties.

Surface Modification of Austenitic Stainless Steel by Means of Low Pressure Glow-Discharge Treatments with Nitrogen

When low temperature nitriding of austenitic stainless steels is carried out, it is very important to remove the surface passive layer for obtaining homogeneous incorporation of nitrogen. In the glow-discharge nitriding technique this surface activation is performed by cathodic sputtering pre-treatment, which can heat also the samples up to nitriding temperature. This preliminary study investigates the possibility of producing modified surface layers on austenitic stainless steels by performing low pressure glow-discharge treatments with nitrogen, similar to cathodic sputtering, so that surface activation, heating and nitrogen incorporation can occur in a single step having a short duration (up to about 10 min). Depending on treatment parameters, it is possible to produce different types of modified surface layers. One type, similar to that obtained with low temperature nitriding, consists mainly of S phase and it shows improved surface hardness and corrosion resistance in 5% NaCl solution in comparison with the untreated steel. Another type has large amounts of chromium nitride precipitates, which cause a marked hardness increase but a poor corrosion resistance. These surface treatments influence also water wetting properties, so that the apparent contact angle values become >90°, indicating a hydrophobic behavior.

Surface modification of tool steel by cathodic cage TiN deposition

ABSTRACT The aim of this work is to investigate the effect of titanium nitride coating for various treatment times (0.5–4 h) by cathodic cage plasma deposition (CCPD) on surface properties of AISI D6 tool steel. The obtained results depict micrometric-sized TiN film deposition under all processing condition with improved surface hardness and corrosion resistance. Raman and EDS analysis are used to calculate N/Ti ratios for stoichiometric calculations of samples. This study depicts that the surface properties of tool steel can be effectively improved by TiN film deposition using CCPD, with low processing time, low processing temperature and better uniformity, as compared to conventional techniques. Additionally, the problems associated with the conventional TiN films such as pores and voids are eliminated. This technique is compatible with industrial-scale applications, and thus results from this study are expected to be beneficial for the surface engineering industry.

Influence of ionic modification of high-speed steel surface on tribological characteristics

The article discusses some ways to improve the wear resistance of technical coatings on the surfaces of cutting tools. These coatings were formed in two stages: diffusion saturation with nitrogen (nitriding) and the use of (Ti, Cr) N solid coatings through the process of applying a cathode arc discharge plasma. The proposed coating option also includes an additional ion doped layer implanted on the previously nitrated surface of high-speed steel. Such a multi-layer coating significantly increases (2.1–2.4 times) the wear resistance of the cutting tool due to the expansion of the stage of normal wear. The influence of 16 chemical elements and four antifriction materials implanted into the base surface on the wear resistance of a high-speed steel cutter with technical surface coating was investigated.

Status of laser transformation hardening of steel and its alloys: a review

The state of laser transformation hardening in surface modification of steel and its alloys is reported in this review paper. The laser hardening process involves the use of high-intensity laser radiation to heat the surface of steel into the austenitic region rapidly. Due to high rates of heat transfer, steep temperature gradients result in rapid cooling by conduction. This causes the transformation from an austenite to a martensite microstructure without the need for external quenching and generates a hard wear-resistant surface. The introduction of high-power lasers, such as neodymium-doped yttrium aluminum garnet (Nd:YAG), diode and fiber lasers, has made laser-assisted hardening an attractive candidate for surface hardening processes. Recently, fiber lasers appeared as a competitor to Nd:YAG and diode lasers for material processing. This review paper is a synopsis of the fundamentals of laser hardening, outlining some of its benefits compared with those of conventional hardening techniques and its industrial applications. A selective review of the experimental and numerical research carried out on steel in this area is also presented. Finally, it is concluded that the overall state of research on laser hardening in surface engineering of steel is well developed, and a still-growing industrial application is observed.

Effect of Nd-YAG laser treatment on corrosion behavior of AISI316L stainless steel in artificial saliva solution

This work aims to study the effect of Nd-YAG laser treatment on surface modification and corrosion behavior of AISI 316L stainless steel which is the most widely used as implant bio material in the artificial saliva solution at 37 ±1°C. The samples were irradiated with Nd:YAG laser with various pulse repetition rates (or frequencies) of 1,3 and 6 Hz and with two wavelengths of 1064 nm and 532 nm at fixed energy of 1000 mj. Microstructure examinations by optical and SEM were performed before and after laser treatment. Corrosion tests were carried out by using potentiostat instrument and the corrosion rate was measured by Tafel extrapolation method, also cyclic polarization was done to study the active- passive behavior of stainless steel 316L in saliva solution. It has been found that the treated samples at different laser conditions have hardness higher than that of untreated sample. The results showed that the hardness increased slightly with decreasing the pulse repetition rate or frequency from 6 to 1 Hz at 1064nm, also a surface modification and grain refinement were noticed. Corrosion results indicated that the treated samples with 1Hz with 532 nm and 1064 nm showed higher corrosion resistance than untreated base alloy and other treated samples.

Synthesis of thin organic layers containing silane coupling agents and azole on the surface of mild steel. Synergism of inhibitors for corrosion protection of underground pipelines

The mechanism of steel inhibition by 1,2,3-benzotriazole (BTA) formulations with organosilanes was studied by electrochemical methods and X-ray photoelectron spectroscopy (XPS). It was shown that the simultaneous introduction of these inhibitors into chloride-containing neutral media significantly reduces the rate of uniform and pitting steel corrosion. The use of scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) made it possible to investigate the distribution of elements in inhibitory formulations of 1,2,3-benzotriazole with organosilanes under various conditions for modification of steel surface. High efficiency of inhibitor compositions is associated with the formation of "polymer-like" protective layers as a result of silanes hydrolysis followed by hydrolytic polycondesation with BTA molecules. It was determined that these species in defined ratios create synergistic compositions with high inhibiting efficiency. The synthesized layers to decrease the adsorption of aggressive chloride anions due to possible negative surface charging and the presence of dense crystal-like siloxane-azole layers tightly bound to metal. The compositions are planned to use in adhesive layers for polymeric tapes used for protection of underground pipelines.

Effect of Plasma Nitriding Pretreatment on the Mechanical Properties of AlCrSiN-Coated Tool Steels.

Surface modification of steel has been reported to improve hardness and other mechanical properties, such as increase in resistance, for reducing plastic deformation, fatigue, and wear. Duplex surface treatment, such as a combination of plasma nitriding and physical vapor deposition, achieves superior mechanical properties and resistance to wear. In this study, the plasma nitriding process was conducted prior to the deposition of hard coatings on the SKH9 substrate. This process was done by a proper mixture of nitrogen/hydrogen gas at suitable duty cycle, pressure, and voltage with proper temperature. Later on, the deposition of gradient AlCrSiN coatings synthesized by a cathodic-arc deposition process was performed. During the deposition of AlCrSiN, CrN, AlCrN/CrN, and AlCrSiN/AlCrN were deposited as gradient interlayers to improve adhesion between the coatings and nitrided steels. A repetitive impact test (200k–400k times) was performed at room temperature and at high temperature (~500 °C) to assess impact resistance. The results showed that the tribological impact resistance for the synthesized AlCrSiN increased because of a progressive hardness support. The combination of plasma nitriding and AlCrSiN hard coatings is capable of increasing the life of molding dies and metal forging dies in mass production.