Surface Of Steel Substrate Research Articles

CORROSION RESISTANT CERAMIC COATING FOR X80 PIPELINE STEEL BY LOW-TEMPERATURE PACK ALUMINIZING AND OXIDATION TREATMENT

In this paper, we discuss the formation of ceramic coatings by a combined processing of low-temperature pack aluminizing and oxidation treatment on the surface of X80 pipeline steel substrates in order to improve the corrosion resistance ability of X80 pipeline steel. First, Fe - Al coating consisting of FeAl 3 and Fe 2 Al 5 was prepared by a low-temperature pack aluminizing at 803 K which was fulfilled by adding zinc in the pack powder. Pre-treatment of X80 pipeline steel was carried out through surface mechanical attrition treatment (SMAT). Further oxidation treatment of as-aluminized sample was carried out in the CVD reactor at 833 K under oxygen containing atmosphere. After 1 h duration in these conditions, ceramic coating consisting of α- Al 2 O 3 was formed by in situ oxidation reaction of Fe - Al coating. Those coatings have been characterized by different techniques including X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscope (EDS), respectively. Ceramic coating shows a dense and uniform microstructure, and exhibits good coherences with X80 pipeline steel substrates. By electrochemical corrosion test, the self-corrosion current density of X80 pipeline steel with as-obtained ceramics coating in 3.5% NaCl solution shows an obvious decrease. The formation of α- Al 2 O 3 ceramic coating is considered as the main reason for the corrosion resistance improvement of X80 pipeline steel.

P(VDF-TrFE) Polymer-Based Thin Films Deposited on Stainless Steel Substrates Treated Using Water Dissociation for Flexible Tactile Sensor Development

In this work, deionized (DI) water dissociation was used to treat and change the contact angle of the surface of stainless steel substrates followed by the spin coating of P(VDF-TrFE) material for the fabrication of tactile sensors. The contact angle of the stainless steel surface decreased 14° at −30 V treatment; thus, the adhesion strength between the P(VDF-TrFE) thin film and the stainless steel substrate increased by 90%. Although the adhesion strength was increased at negative voltage treatment, it is observed that the crystallinity value of the P(VDF-TrFE) thin film declined to 37% at −60 V. In addition, the remanent polarization value of the P(VDF-TrFE) thin film declined from 5.6 μC/cm2 to 4.61 μC/cm2 for treatment voltages between −5 V and −60 V. A maximum value of approximately 1000 KV/cm of the coercive field value was obtained with the treatment at −15 V. The d33 value was approximately −10.7 pC/N for the substrate treated at 0 V and reached a minimum of −5 pC/N for treatment at −60 V. By using the P(VDF-TrFE) thin-film as the sensing material for tactile sensors, human pulse measurements were obtained from areas including the carotid, brachial, ankle, radial artery, and apical regions. In addition, the tactile sensor is suitable for monitoring the Cun, Guan, and Chi acupoints located at the radial artery region in Traditional Chinese Medicine (TCM). Waveform measurements of the Cun, Guan, and Chi acupoints are crucial because, in TCM, the various waveforms provided information regarding the health conditions of organs.

Electrochemical nucleation and growth of Sn onto double reduction steel substrate from a stannous fluoborate acid bath

Cyclic voltammetry (CV), chronoamperometry (CHR) in conjunction with scanning electron microscopy (SEM) technique have been performed to study the electrodeposition behavior of tin onto double reduction steel substrate from a stannous fluoborate acid bath. Results show that, under the experimental conditions, the initial reduction process of tin is controlled by diffusion and follows the three-dimensional (3D) nucleation and subsequent grain growth mechanism. With the increase of the applied cathodic overpotentials, the nucleation type of tin changes from progressive mechanism to instantaneous mechanism. When the deposition overpotential is high, the electrode surface is fully covered with tin deposits in short times that the current–time transient is composed of the tin nucleation current and the current attributed to proton reduction on the tin growth centers while the current due to proton reduction on the steel surface should be considered as well at low deposition overpotentials. Results also reveal that both the tin nucleation and proton reduction rate constant increase with increasing the cathodic overpotentials, and the proton reduction rate constant on the steel substrate surface is larger than that on the tin growth centers. The diffusion coefficient of tin species is found to be 1.24E−5cm2s−1.

Study on the Corrosion Resistance of Ti(CN) Composites Coating

Metal composites coating of Ti (CN) was made on the surface of Q235 steel substrate by reaction nitrogen are welding cladding process, and potted with low temperature epoxy, di-n-butyl phthalate and T31, the mass ratio was 10:2:1.5. To evaluate the corrosion resistance of Ti (CN) coating, the specimens were immersed in 5% sulfuric acid and 3.5% sodium chloride to calculate corrosion rate by potentiodynamic polarization measurement. The corrosion resistance of Ti (CN) is improved by 3.45 times in 5% sulfuric acid and 4.39 times in3.5% sodium chloride.

A systematic laboratory study on an anticorrosive cool coating of oil storage tanks for evaporation loss control and energy conservation

The composition and manufacturing process of a three-layer anticorrosive cool coating for oil storage tanks are introduced. The optical, indoor thermal and physicochemical properties were systematically investigated. In addition, the outdoor cooling effect and the reduction of evaporation losses of crude oil were predicted. The coating developed has high solar reflectance and thermal emittance and thus good indoor and outdoor temperature reduction effects. The unique structural design and the careful selection of ingredients endow the coating with low thermal conductivity and good resistance to dirt, weather, salt spray and chemicals. The selected epoxy functional saline couple agent creates a chemical bridge between the coating's binder and the surface of carbon steel substrates and improves the adhesion of the coating.

Formation of Fe–Al intermetallic coating on low-carbon steel by a novel mechanical alloying technique

A novel coating method, mechanical alloying, was used to layer a Fe–Al solid solution on the surface of low-carbon steel. During the mechanical alloying process, moving balls and powder particles impacted the substrate surface. The coating process was performed in a planetary ball-mill using a milling time that varied from 1 to 10h, a ball-to-powder ratio of 10:1, and a ball-mill velocity of 200rpm. Al2024 powder was used as a new raw material for metal deposition. The surface morphology of the coatings was characterized by scanning electron microscopy (SEM). Local compositional analysis and intermetallics formation were analyzed by electron microscopy with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results revealed that a Fe–Al coating was formed on the surface of the low-carbon steel substrate by the formation of Fe–Al intermetallics.

Thermal Barrier Coatings on Laser Surface Modified AISI H13 Tool Steel Using Atmospheric Plasma Spray Technique

This paper presents yttria-stabilized zirconia (YSZ) coating deposition on laser surface modified H13 tool steel using atmospheric plasma spray (APS) technique. A Praxair Plasma Spray System with SG-100 gun was used to deposit coating materials on laser-modified H13 tool steel substrate surface. A bond coat layer material was NiCrAlY alloy while the top coat was yttria stabilized zirconia (YSZ) with powder size distribution range of-106 μm to +45 μm. A 23 design of experiment (DOE) was used to deposit bond coat and top coat powders with three controlled factors of input current, powder feed rate and stand-off-distance. The design was optimised for minimum porosity and maximum hardness. The coating thickness and percentage of porosity were measured using IM7000 inverted optical microscope. Hardness properties of top coating layer were measured by using MMT-X7 Matsuzawa Hardness Tester Machine with Vickers hardness scale. The microscopy findings indicated variations of coating thickness at different parameters settings. Samples at the highest current and powder feed rate and lowest stand-off distance settings produced a lower porosity percentage and higher hardness. A higher powder feed rate with the smallest stand-off-distance allowed melted powders to travel uniformly onto the substrate surface. These findings were significant to development of thermal barrier coatings on semi-solid forming die surface.

Synthesis and Characterization of Modified Nano-TiO2 Films for Corrosion Protection of Stainless Steel

A TiO2 film and a B-Fe-Ce-modified TiO2 film were prepared on the surface of 316L stainless steel (316L SS) substrates by a sol-gel and dip-coating method. The corrosion resistance of the films and their protective properties for the stainless steel were investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curve measurements. The results showed that the TiO2 film and the B-Fe-Ce-modified TiO2 film were composed of anatase TiO2 nanoparticles with the diameters about 15 nm and 10 nm, respectively. The EIS results suggested that the B-Fe-Ce-TiO2 film could provide more effective corrosion protection for 316L SS in 0.5 M NaCl solution. The potentiodynamic anodic polarization curve of the B-Fe-Ce-TiO2/316L SS electrode in the above solution showed a larger stable passive region and a higher breakdown potential (Eb ) than that of the TiO2/316L SS.

Microstructure and Interface of TiC <i>In Situ</i> Synthesized Reinforced Steel-Based Surface Composite Prepared by V-EPC Infiltrating Method

In order to optimize the processing parameters of TiC/steel composite materials, in-situ TiC particle reinforced steel-based surface composites were prepared by vacuum evaporative pattern casting (V-EPC) infiltration process, and the structure and interface of the composites were investigated. The results show that, TiC particle size with Ti-C-20wt%Fe reaction system was much smaller than the composite with Ti-C reaction system in the same location of the composites. In the composites, the TiC particle size and volume fraction increased and spherical degree dropped from the tradition layers (interface between the substrate and the composite layer) to the outer surface. But the increase of TiC particle size (1-3μm) and volume fractions (25.8%-43.5%) in the composite with Ti-C-20wt%Fe reaction system was obviously lower than that of TiC particle size (1-10μm) and volume fractions (12.3%- 67.7%) in the composite with Ti-C reaction system. The bond zone between TiC particles and the matrices was totally metallurgical bonding without apparent interface. Comparing with the composite with Ti-C-xFe reaction system, the tradition layer with Ti-C reaction system has a poorer internal quality. The forming process of TiC in situ synthesized reinforced steel substrate surface composites prepared by V-EPC infiltrating process was infiltrating of the melting and carbothermal reactions of C and Ti powder the result of joint action.

Microstructure and Abrasion Wear Resistance of Thermally Sprayed Cermet Coatings

Abstract WC/10Co4Cr and WC/20CrC7Ni powders were sprayed onto the surface of low-carbon steel substrates using the high velocity oxygen fuel (HVOF) spraying method. Microstructure of the obtained coatings was evaluated by scanning electron microscopy (SEM). X-ray diffraction (XRD) analysis as well as hardness and porosity testing were performed on the samples. The abrasion wear resistance of the coatings was determined using the rubber wheel abrasion test. The mass loss rate (mg/h) of the samples was measured and the test results showed that the WC-CrC-Ni coating has better abrasion wear properties than the WC-CoCr coating.

Microstructures of Ni–AlN composite coatings prepared by pulse electrodeposition technology

Ni–AlN composite coating was fabricated onto the surface of steel substrates by using pulse electrodeposition (PED) technique in this work. The effect of pulse current on the nucleation and growth of grains was investigated using transmission electronic microscopy (TEM), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and atomic force microscopy (AFM), respectively. The results show that the contents of AlN nanoparticles increase with density of pulse current and on-duty ratio of pulse current increasing. Whereas the size of nickel grains decreases with density of pulse current increasing and on-duty ratio of pulse current decreasing. Ni–AlN composite coating consists of crystalline nickel (∼68nm) and AlN particles (∼38nm). SEM and AFM observations show that the composite coatings obtained by PED showed more compact surfaces and less grain sizes, whereas those obtained by direct current electrodepositing have rougher surfaces and bigger grain sizes.

Study on TiAl(CN) Particle Reinforce Composites Coating Prepared by Reaction Nitrogen Arc Welding Cladding Process

Particle reinforce composites coating of TiAl(CN) was made on the surface of Q235B steel substrate by reaction nitrogen arc welding cladding process, which take the titanium powder, aluminum powder and the graphite powder as original material. The microstructures, structure and the phase of the coatings were investigated by scanning electronic microscope, X-ray diffract instrument, micro-hardness, reciprocating friction testing machine. The result indicated that the TiAl(CN) coating has a metallurgy union with the substrate, the phase of the coatings are mainly composed of TiAl(C 0.51 N 0.12), AlFe3 and FeC. The microhardness and anti-abrasive performance of the TiAl(CN) coating is better than the Ti(CN) coating processed by tungsten nitrogen arc surfacing welding process.

Mechanical properties, wear, and corrosion of boronized N80 tube steel

The effect of boronizing on the mechanical properties, wear, and corrosion of boronized N80 tube steel is studied. A dual-phase boride layer consisting of the FeB and F2B phases is formed on the surface of steel substrate within the hardness range 1220–1340 HV. A special setup was designed to use smaller amounts of the boriding agent and accelerate the process of cooling of the pipe. In order to meet the tensile properties of N80 steel required by the API SPEC 5 L, four cooling methods were employed. The procedure of fan cooling with a graphite bar inside the boriding agent resulted in the highest mechanical properties in accordance with the mechanical properties of the API SPEC 5 L. The boronized N80 steel reveal a high wear resistance under the conditions of dry sliding and excellent corrosion resistance in the as-received oil-field water from the Jilin oil field, Northeast China.

Research on Interfacial Cracking of a Cr Coating/Steel Substrate with and without Laser Pre-Quenching Treatment under Thermal Fatigue Loading

The interfacial cracking behaviors of a chromium (Cr) coating/laser pre-quenched steel substrate system and a Cr coating/original steel substrate system under thermal fatigue loading were investigated in this work. The experiment results show that the Cr coating on the pre-quenched substrate surface exhibited a higher resistance of interfacial cracking than that of the Cr coating on the original substrate surface under the same loading condition. This indicates the technology of laser pre-quenching of steel substrate surface prior to plating the Cr coating can improve the interfacial adhesion properties between the coating and substrate.

Investigating the microstructure and mechanical behaviors of DLC films on AISI52100 bearing steel surface fabricated by plasma immersion ion implantation and deposition

The microstructure and mechanical properties of diamond-like carbon (DLC) films fabricated on an AISI52100 bearing steel substrate surface by plasma immersion ion implantation and deposition (PIIID) were studied. Atomic force microscope (AFM) observation reveals that the DLC film has an extremely smooth surface, and high uniformity and efficiency of space filling over large areas. Raman spectroscopy analysis indicates that DLC films are mainly constituted by amorphous and crystalline phases, with a variable ratio of sp2/sp3 carbon bonds, and sp3 bond content of more than 10%. The maximum nanohardness and elastic modulus of the DLC film are 40GPa and 430GPa, and increase by 263.6% and 95.5%, respectively. The friction and wear results exhibit that the friction coefficient against an AISI52100 steel ball decreases from 0.87 to 0.20. The corrosion polarization curves in a 3.5% saturated NaCl solution shows that the corrosion resistance of DLC/AISI52100 samples is much better than that of bearing steel substrate. Compared with the bare bearing steel, the surface mechanical property of the DLC/AISI52100 sample is improved significantly.

Microstructure and wear resistance of molybdenum based amorphous nanocrystalline alloy coating fabricated by atmospheric plasma spraying

Molybdenum (Mo) based amorphous nanocrystalline coating was deposited on the surface of plain carbon steel substrates by atmospheric plasma spraying (APS). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the microstructures of Mo-based powder and coating. The surface hardness of substrate and coating were determined using a Vickers hardness tester, and microhardness profile of cross-section was realized by a Vickers microhardness tester. Wear tests were carried out using a pin on plate type tester by changing the load and linear speed. The results indicated that the as-prepared Mo-based coating was mainly composed of Fe0.54Mo0.73, Fe3Mo, Cr9Mo21Ni20, Fe3B and Cr0.46Mo.4Si0.14 phases. The average grain size of Mo-based coating was 22–32nm. The coating presented a dense layered structure and its thickness was about 250μm. The surface hardness of Mo-based coating was as high as 9.2GPa, which was 8 times of substrate. The microhardness along the cross-section gradually decreased from coating to substrate. The wear resistance of Mo-based coating was far better than that of substrate.

A synthesis of graphene/Co3O4 thin films for lithium ion battery anodes by coelectrodeposition

We report on a facile strategy for the direct and uniform deposition of a graphene/Co3O4 thin film onto stainless steel substrate (SS) through cathodic deposition. Graphene oxides (GOs) were treated with poly(ethyleneimine) (PEI) which acted as a stabilizer and binder between GOs and cationic metal precursor. For the formation of PEI‐modified GOs (PEI-GOs) and Co2+ complexes, the PEI-GOs dispersion was mixed with aqueous phase of Co(NO3)2, then, the solution was used as the plating bath for coelectrodeposition. Results showed that the PEI-GOs and cobalt oxides were uniformly distributed on the surface of SS evidenced by field emission scanning electron microscopy. The prepared graphene/Co3O4 film was employed as an anode material for lithium ion batteries, and it exhibited not only an enhanced cycleability but also high electronic conductivity.

Investigation of Boronizing Kinetics of AISI 51100 Steel

In this study, some mechanical properties of borided AISI 51100 steel with high C concentration were investigated. Boronizing heat treatment was carried out in solid medium consisting of Ekabor-II at 850, 900, and 950 °C for 2, 4, 6, and 8 h. Morphology and mechanical properties of boride layer, and the effect of chemical composition on properties and kinetics of borides were investigated. The results of this study indicated that the morphology of the boride layer has a saw-tooth nature, and its hardness is over 1500 HV. Depending on process time and temperature, the depth of boride layer ranged from 30 to 106 μm. Optical and SEM studies and XRD analysis revealed that borides formed on the surface of steel substrates have dominantly single Fe2B boride phase in addition to small amount of Cr2B.

Laser-induced reaction of Si powder with a steel substrate

We have determined the phase composition and microhardness of coatings produced by the laser melting of silicon powder on the surface of steel substrates. Laser exposure leads to the formation of iron silicides on the substrate surface. The iron content of the silicides depends on the effective laser power and increases from that of FeSi2 to Fe0.9Si0.1. The coatings have the highest microhardness at an effective power of ≏ 400 W s/m, which corresponds to the highest FeSi content.

Influence of Laser Remelting on Tensile Properties of Nanocomposite Ni–Al<sub>2</sub>O<sub>3</sub> Coatings

Ni­Al2O3 nanocomposition coatings were fabricated onto the surface of steel (grade 45) substrates using jet electroplating technology followed by laser remelting. The microstructure of the Ni­Al2O3 nanocomposite coating and the laser remelted layer were analysed. The surface composition was analysed using energy-dispersive X-ray spectroscopy (EDS). The tensile properties of the composite coating before and after laser irradiation were measured. The results show that for optimized testing parameters jet electroplating technology can produce 3.58mass%. Ni­Al2O3 nanocomposite coatings. The tensile strength and percentage elongation of the test specimen with nanocomposite coating are better than substrate material. Laser remelting further improved the tensile strength and percentage elongation of the test-specimen. [doi:10.2320/matertrans.M2012256]