Surface Roughness Of Steel Research Articles

ZnDTP-Derived Tribofilm Formation Process and the Wear of Roughness Peaks on a Rough Steel Surface

ZnDTP-Derived Tribofilm Formation Process and the Wear of Roughness Peaks on a Rough Steel Surface

Surface morphology evolution and tribological behavior in nanosecond pulsed laser polishing of S136 mold steel

Laser polishing (LP) is anticipated to become a new generation of surface polishing technology for the industrial field due to its high efficiency, reliability, and environmental friendliness, while few studies have reported the effect of LP on tribological behavior. Herein, the surface morphology, surface roughness, phase composition, surface hardness, and tribological behavior of S136 mold steel after nanosecond pulsed LP were investigated. The results of the orthogonal experiment suggested that the effect on surface roughness was in the following order: laser fluence > scanning speed > overlap factor along Y direction. A smooth and defect-free surface with a surface roughness Sa of 80 nm and a surface roughness reduction rate of 55.8% was achieved using the optimal LP parameters, and the LP mechanism was identified as the shallow surface melting. The wear tests indicated that LP weakened the wear resistance of S136 mold steel, which was attributed to the appearance of the γ-Fe phase on polished surface resulting in an 8% decrease in surface hardness, but this phenomenon is tolerable and controllable. Moreover, a combined action of abrasive wear and adhesive wear was confirmed on the LP specimens, whereas the abrasive wear was determined on the original specimen.

Fenugreek seed and cape gooseberry leaf extracts as green corrosion inhibitors for steel in the phosphoric acid industry

Phosphoric acid is the core material for the fertilizer industry; however, it is incredibly corrosive to manufacturing plants’ structures, mainly steel. Corrosion is one of the most severe problems encountered during phosphate fertilizer manufacturing. Recently, plant extracts have been commonly used as corrosion inhibitors because they are cheap and environmentally friendly. Steel corrosion in a 20% aqueous phosphoric acid solution in the absence and presence of fenugreek seed (Fen) or cape gooseberry leaf (CgL) extracts was investigated using the electrochemical impedance spectroscopy technique, potentiodynamic polarization measurement, scanning electron microscope, and quantum chemical calculations. Fourier Transform Infrared, FTIR, was used to identify the functional groups in Fen and CgL extracts. The inhibition efficiency for steel in 20% aqueous phosphoric acid was roughly equal to 80% for 0.4 g/L CgL and 1.2 g/L Fen extracts. A scanning electron microscope showed that the chemical constituents of extracts block the surface roughness of steel, decreasing the corrosion rate. The activation parameters indicated the effectiveness of the extracts at a higher temperature. Measurements of the potential of zero charges showed that the steel surface is positively charged in the phosphoric acid solution. Quantum chemical computations were also employed to examine the corrosion inhibition mechanisms of the natural extracts.

Influence of chemical etchings on surface properties, in-vitro degradation and ion releases of 316l stainless steel alloy for biomedical applications

Different surface treatments are applied to improve the surface properties of metallic biomaterials. Chemical etching is one of the common techniques used for roughening the surface. In this regard, the effects of different chemical media on the surface roughness, degradation, and ion release of 316L SS steel were investigated in this study. The 316L SS steel was exposed to chemical etching in six different chemical media including HNO3, H2SO4, HCl, HClO4, NaOH and Na2CO, at four different concentrations (1, 2, 4, and 8 Molar), and at three immersion times (10, 60, and 180 min). SEM, EDS, and XRD analyses were used to examine the morphological and chemical impacts of chemical etching on sample surfaces, and roughness was measured on all sample surfaces. The effect of surface treatment on the degradation and ion release of the samples was comparatively examined. Characterization analyses indicated that the HNO3, H2SO4, and HCl media did not cause a significant reaction on the surface of the 316L SS. On the other hand, different phases were observed on the sample surfaces exposed to HClO4, NaOH, and Na2CO3 media. It was determined that the roughness had no linear correlation with the concentration and immersion time, and similarly, the degree of degradation and amount of ion release displayed no change depending on the roughness. Samples etched in H2SO4, HClO4, NaOH and Na2CO3 provided the highest roughness. It was found that H2SO4 caused a significant increase in the amount of ion release.

Reduction in the Volumetric Wear of a Ball Polishing Tool Using Ultrasonic-Vibration-Assisted Polishing Process

Ultraprecision freeform polishing using a bonnet or a felt ball mounted on a polishing head plays an important role in the mold and lens production industries. The volumetric wear of a bonnet or a felt polishing ball is still a problem to be solved. The objective of this study was to develop an ultrasonic-vibration-assisted ball polishing process on a CNC machining center to improve the surface roughness of a STAVAX mold steel and to reduce the volumetric wear of the polishing ball. The optimal combination of the ultrasonic-vibration-assisted ball polishing parameters for a plane surface was determined by conducting the Taguchi L18 matrix experiments, ANOVA analysis, and verification experiments. The surface roughness of the polished specimens was improved from the burnished surface roughness of Ra 0.122 μm to Ra 0.022 μm. In applying the optimal plane surface ball burnishing and vibration-assisted spherical polishing parameters sequentially to a fine-milled and burnished aspherical lens surface carrier on a five-axis machining center, the surface roughness of Ra 0.014 μm was obtainable. The improvement in the volumetric wear of the polishing ball was about 62% using the vibration-assisted polishing process compared with the nonvibrated polishing process.

GRAVIMETRIC AND ELECTROCHEMICAL TEST OF ETLINGERA ELATIOR INFLORESCENCE EXTRACT AS GREEN CORROSION INHIBITOR

At present, organic corrosion inhibitors which are commonly used such as silicate and phosphate have a high level of toxicity. It has prompted the search for green corrosion inhibitors because of its eco-friendly properties and has a lower level of toxicity. Therefore, this study has been conducted to investigate the inhibition efficiency (IE%) and corrosion rate of mild steel in 0.5 M HCl acidic medium. The data obtained through weight loss and the electrochemical method at various concentrations and temperatures. The surface morphologies was observed using Scanning Electron Microscope (SEM). Different experimental conditions were also used such as electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PPC). EIS findings revealed that the addition of studied inhibitors prevented the degradation of mild steel in HCl solution, hence leading to a high value of polarization resistance compared to the blank solution. Besides that, the PPC results suggested that the tested samples had a mixed-type effect which decreased the anodic and cathodic corrosion reactions. Surface characterization by SEM illustrated a notable decrease in surface roughness of mild steel after the addition of inhibitors. Outcomes from the present study indicates that the Etlingera Elatior inflorescence extract acts as a good corrosion inhibitor for mild steel sample in HCl solution with IE% value above 93.63 %. Formation of the protective layer becomes weaker as the temperature raises.

Phenotypic and genotypic characterization of multi-drug resistant, biofilm forming, human invasive strain of Salmonella Typhimurium SMC25 isolated from poultry meat in India

Emergence of highly virulent and multi-drug resistant (MDR) strains of Salmonella in food products significantly impacts public health and demands continuous monitoring for their presence in the food chain. The ability of Salmonella to form biofilms under harsh environmental conditions accompanied by MDR serotypes underscores an important food safety threat. This study aimed to isolate, identify and characterize MDR, biofilm-forming Salmonella from local Indian dairy and meat products (n = 60). All of the 24 isolates of Salmonella produced biofilm and were categorized as strong (16.6%), moderate (58.3%), and weak (25%) biofilm producers. Multiple antimicrobial resistance (MAR) index of all the Salmonella isolates was ≥0.2. The strongest biofilm forming poultry meat isolate, Salmonella SMC25 demonstrated intermediate to complete resistance to 14 of 22 different antibiotics tested. Epifluorescence microscopy showed that biofilm formation initiated as early as 4 h, reaching zenith within 96 h and much denser and robust biofilm is formed on rough stainless steel (SS316) surface compared to smooth glass surface. The results corroborated with increased temporal production of exopolysaccharides (EPS), high cell surface hydrophobicity and upregulation of marker genes vital to biofilm-formation in Salmonella. Significantly, SMC25 was found to adhere and invade mammalian cell lines Caco2 and HepG2, thus posing a serious food safety threat. This study is important in comprehending the prevalence of multidrug resistant, biofilm-forming, invasive strains of foodborne Salmonella in Indian food products and is important for effective risk assessment besides ensuring better food safety and public health.

Prediction of Surface Roughness of U71Mn Steel Milling Based on RBF Neural Network

In order to predict the surface roughness of U71Mn high manganese steel before actual milling operation, an orthogonal experiment was designed. Based on the intelligent algorithm of Radial Basis Functions (RBF) neural network, an accurate prediction model of surface roughness is done with MATLAB. By comparing the predicted data of RBF neural network model with the actual measured data, it is proven that the model is accurate and effective.

Change in Dimensions and Surface Roughness of 42CrMo4 Steel after Nitridation in Plasma and Gas

The influence of plasma nitriding and gas nitriding processes on the change of surface roughness and dimensional accuracy of 42CrMo4 steel was investigated in this paper. Both processes almost always led to changes in the surface texture. After plasma nitriding, clusters of nitride ions were formed on the surface of steel, while gas nitriding very often led to the new creation of a formation of a “plate-like” surface texture. In both cases of these processes, a compound layer in specific thickness was formed, although the parameters of the processes were chosen with the aim of suppressing it. After the optimizing of nitriding parameters during nitriding processes, it was found that there were no changes in the surface roughness evaluated using the Ra parameter. However, it turned out that when using a multi-parameter evaluation of roughness (the parameters Rz, Rsk and Rku were used), there were presented some changes in roughness due to nitriding processes, which affect the functional behavior of the components. Roughness changes were also detected by evaluating surface roughness profiles, where nitriding led to changes in peak heights and valley depths. Nitriding processes further led to changes in dimensions in the form of an increase of 0.032 mm on average. However, the magnitude of the change has some context on chemical composition of material. A larger increase in dimensions was found with gas nitriding. The change in the degree of IT accuracy is closely related to the change in dimension. For both processes, there was a change of one degree of IT accuracy compared to the ground part (from IT8 to IT9). On the basis of the achieved dimensional accuracy results, a coefficient of change in the degree of accuracy IT was created, which can be used to predict changes in the dimensional accuracy of ground surfaces after nitriding processes in degrees of accuracy IT3–IT10. In this study, a tool for predicting changes in degrees of accuracy of ground parts after nitriding processes is presented.

Ureidopyrimidinone-containing Poly(amino ester) for corrosion inhibition of mild steel in acidic medium

Ureidopyrimidinone-containing Poly(amino ester) (UPy-D400-PEGDA) was synthesized by the Michael addition reaction of Poly(ethylene glycol) diacrylate and polyether amine grafted 2-ureido-4[1H]-pyrimidinone motifs, and its corrosion inhibition efficiency on Q235 steel in 1 mol/L HCl medium was studied by polarization curve and electrochemical impedance spectroscopy, as well as corrosion product analysis. UPy-D400-PEGDA is a mixed-typed corrosion inhibitor that mainly suppressed the cathode, can form a protective film on the surface of mild steel to suppress the corrosion of oxygen and chlorine in acid medium. Corrosion inhibition efficiency was gradually enhanced with the increase of the concentration of UPy-D400-PEGDA. The corrosion inhibition efficiency reaches 98.80% when the inhibitor concentration is 500 mg/L. The surface roughness of mild steel in 1 mol/L HCl solution without UPy-D400-PEGDA was 3.891 μm, while the roughness of mild steel with UPy-D400-PEGDA concentration of 500 mg/L was only 0.636 μm. The inhibition mechanism was elucidated using quantum chemical calculation.

Effect of Schiff's bases on corrosion protection of mild steel in hydrochloric acid medium: Electrochemical, quantum chemical and surface characterization studies

Schiff's bases such as (E)-3-(3-hydroxybenzylideneamino)-2-(3-hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (SB-1) and (E)-3-(5‑bromo-2-hydroxybenzylideneamino)-2-(5‑bromo-2-hydroxyphenyl)-2,3-dihydraquinazolin-4(1H)-one (SB-2) were synthesized and investigated to the surface interactions & corrosion protection performance on mild steel (MS) in 2 M HCl medium by means of weight loss, electrochemical polarization and electrochemical impedance spectroscopic (EIS) techniques. Tafel polarization measurements showed that, the synthesized compounds were exhibited as mixed type (cathodic / anodic) inhibitors and the maximum protection efficiencies of 86.44% and 87.36% for SB-1 and SB-2 respectively were observed at optimized concentration. The corrosion control of MS in presence of inhibitors could evaluate through adsorption phenomenon and fitted to Langmuir's adsorption isotherm. Activation energy (Ea) values in absence of the inhibitor is minimum 51.45 kJ mol−1 and higher values of 89.98 kJ mol−1 and 70.09 kJ mol−1 in the presence of SB-1 and SB-2 respectively. Thermodynamic adsorption parameters such as ∆Hads, ∆Gads & ∆Sads were correlated to the corrosion inhibition process. Quantum chemical analysis revealed the nature of chemical interaction established between the inhibitor molecules and metal atoms. The change in surface morphology of mild steel and chemical interactions of inhibitor molecules on specimen surface were evaluated through FT-IR, Scanning electron microscopic linked with EDX, Atomic force spectroscopy and Contact angle techniques. Atomic force microscopic results revealed that, an average roughness of the mild steel surface has been reduced from 443 nm to 11.0 nm and 26.9 nm in presence SB-1 and SB-2 respectively.

Experimental investigation of effect of welding parameters on surface roughness, micro-hardness and tensile strength of AISI 316L stainless steel welded joints using 308L filler material by TIG welding

Tungsten inert gas (TIG) welding is type of arc welding with area of applications in food industry, pharmaceutical industry, chemical plants, marine, aerospace, medical devices, and implants, etc. TIG welding process involve several parameters. Many parameters are controllable by the operator, and these parameters have a direct or indirect impact on the microstructure and mechanical properties of the joints. In the present study, three TIG welding parameters, arc current, voltage, and shielding gas flow rate, were changed up to three levels and their effects on surface roughness, hardness and tensile strength were investigated. Experiments were carried out on a 3 mm thick plate of austenitic stainless steel AISI 316L utilizing a TIG welding equipment and were designed according to Taguchi L9 orthogonal array (OA). ER308L was used as filler material. Results were analyzed using signal to noise S/N ratio and analysis of variance. It was observed that, for optimization of each response, arc current is the most influential factor. Minimum surface roughness was achieved at parametric combination of current 125 A, voltage 18 V and gas flow rate 12 L/min. Maximum hardness was achieved at parametric combination of current 125 A, voltage 20 V and gas flow rate 9 L/min. Maximum tensile strength was achieved at parametric combination of current 100 A, voltage 18 V and gas flow rate 6 L/min.

Optimization on Material Removal Rate and Surface Roughness of Stainless Steel 304 Wire Cut EDM by Response Surface Methodology

In this work, wire cut electrical discharge machining (WEDM) is used for the material removing processes; it is utilized for machining conductive parts where it is required to produce complicated shapes, new profiles, new geometry, new product development, and high-accuracy components. This machining process is best suitable for high-end applications such as aerospace, automations, automobile, and medical devices. At present, most of the industrial sectors choose the WEDM process because it is used to develop products in a very short development cycle and at a better economic rate. In this paper, the selected complex geometry of the metal sample was eroded away from the wire during the WEDM process, which eliminates mechanical tensions during machining. The effect of different WEDM operation variables set as wire speed, wire tension, discharge current, dielectric flow rate, and pulse on and off time on the parameter, stainless steel 304 material removing rate (MRR) using RSM, has been studied. The MRR will be maximized if the optimum sets of operational variations are used and also achieve a superior surface finish.

Enhanced corrosion performance of S136 steel after nanosecond pulsed laser polishing

Laser polishing (LP) has aroused great interest in view of its potential application in the mold industry, whereas few studies have reported the effect of LP on corrosion performance. Herein, the surface morphology, surface roughness, X-ray photoelectron spectroscopy analysis and corrosion performance of S136 steel after nanosecond pulsed LP were investigated and compared with those of mechanical polishing (MP). A smooth and defect-free surface of the LP specimen was obtained with a surface roughness of 0.078 μm and a surface roughness reduction rate of 56.9%. The corrosion current density of the LP specimen was 0.164 μA/cm2, which was 4.2% and 12.8% of the original and MP specimens, respectively. And prominent decreased in the number and diameter of corrosion pittings on surface of the LP specimen compared with the original and MP specimens. These results demonstrate that LP significantly improves the corrosion performance of the S136 steel, which is mainly attributed to the increase of Cr2O3 in passive film, the formation of melting layer and the decrease of non-metallic inclusions on surface of the LP specimen. Our findings provide a scientific approach for greatly improving corrosion performance while reducing surface roughness of steel.

Corrosion resistance of 3D printed SS316L post-processed by ultrasonic shot peening at optimum energy level

The layer-upon-layer nature of production by additive manufacturing (AM) made surface treatment as mandatory post-processing for increasing the surface integrity and subsequent tribological properties. In the present work an experimental study was carried out to understand how the ultrasonic shot peening (USP) enhances the corrosion rate, surface compressive residual stress, surface roughness and hardness of stainless steel 316 manufactured by selective laser melting (SLM). In order to do so, series of USP experiments carried out based on full factorial design taking into account the effects of ultrasonic power, processing time, and ball diameters on foresaid responses. Multi-objective optimization of process using desirability approach function was performed to obtain a process window including trade-off between energy consumption and sample’s quality characteristics. The optimization results revealed that it is not possible to have minimum energy and the best product’s quality at same time. In other word, to fabricate samples with best quality characteristics, more energy needs to be consumed. The optimum sample was selected through the trade-off graph based on the transition point where after this point the energy consumption dramatically increases but no further improvement in product’s quality characteristics are attained. By identifying the optimum sample, series of surface integrity examination tests were carried out to show the efficiency of USP on enhancement the surface integrity and corrosion properties of AM material. It was found that the sample processed by USP at optimum parameter setting by ultrasonic power of 60%, process time of 15 min, and ball diameter of 6 mm is an optimum process setting that meets the condition described for transition point and causes 120% improvement in corrosion rate.

Wetting and Imbibition Characteristics of Pseudomonas fluorescens Biofilms Grown on Stainless Steel.

This study aims to provide insights into biofilm resistance associated with their structural properties acquired during formation and development. On this account, the wetting and imbibition behavior of dehydrated Pseudomonas fluorescens biofilms grown on stainless steel electropolished substrates is thoroughly examined at different biofilm ages. A polar liquid (water) and a non-polar liquid (diiodomethane) are employed as wetting agents in the form of sessile droplets. A mathematical model is applied to appraise the wetting and imbibition performance of biofilms incorporating the evaporation of sessile droplets. The present results show that the examined biofilms are hydrophilic. The progressive growth of biofilms leads to a gradual increase of substrate surface coverage─up to full coverage─accompanied by a gradual decrease of biofilm surface roughness. It is noteworthy that just after 24 h of biofilm growth, the surface roughness increases about 6.7 times the roughness of the clean stainless steel surface. It is further found that the imbibition of liquid in the biofilm matrix is restricted only to the biofilm region under the sessile droplet. The lack of further capillary imbibition into the biofilm structure, beyond the droplet deposition region, implies that the biofilm matrix is not in the form of an extended network of interconnected micro/nanopores. All in all, the present results indicate a resilient biofilm structure to biocide penetration despite its hydrophilic nature.

Novel nitrogen based heterocyclic compound as Q235 steel corrosion inhibitor in 15% HCl under dynamic condition: A detailed experimental and surface analysis

The present research explores the synthesis of three heterocyclic rings of pyrazol, pyran, and pyrimidine (Py-OH) in one single compound using a multicomponent synthesis approach and its application for the protection of tubular steel (Q235 steel) in acidizing solution (15% HCl) under the dynamic condition at 1500 rpm using weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP). Py-OH's maximum inhibition performance result is 94.46% (200 mg/L). The results of EIS and PDP reveal the corrosion process is charge transfer controlled, and Py-OH acts as a mixed type inhibitor. The maximum increase in Rct value is 393.7 Ω cm2, and the decrease in icorr value is 23 μA/cm2. The adsorption of Py-OH obeyed the Freundlich isotherm. The value of Ea is 80.17 kJ/mol. The protection ability of Py-OH falls as the temperature rises from 308 K to 338 K. The results of SEM, EDX and AFM confirmed the inhibitor layer formation that corresponds to the decrease in surface roughness of Q235 steel, supporting its corrosion protection excellency. Furthermore, the results of XPS further enriched the Py-OH adsorption using the lone pair electrons residing over the N and S.

Effect of multifunction cavitation-treated carbon steel surface on fracture toughness

Improving the strength of an object by surface treatment inevitably trades off strength and ductility, and also reduces toughness. In this study, carbon steel was treated by a surface modification technique, referred to as multifunction cavitation (MFC), and the improvement of strength and toughness was investigated. Peening marks, pits, and rust were observed in the MFC-treated carbon steel as the processing time increased. In addition, the surface roughness of MFC-treated carbon steel increased and the surface potential decreased. Hardness and compressive residual stress increased most under the condition of processing time of 5 min. Charpy impact tests were performed to evaluate toughness. The transition region between the untreated material and the MFC-treated material after the Charpy impact tests was 280–380 K. The MFC-treated material had a lower transition temperature and higher absorption energy than the untreated material, indicating that MFC treatment was effective in improving toughness.

Effect of nitriding on mechanical and microstructural properties of Direct Metal Laser Sintered 17-4PH stainless steel

In this work, the effect of the nitriding process on microstructure and mechanical properties of additively manufactured (AM) 17-4PH stainless steel is investigated. The nitriding was performed at 530 °C, 560 °C, and 580 °C for 2 h. The nitriding process improves the hardness and surface roughness of the AM 17-4PH steel. Detailed microstructural characterizations of both as-built and nitride samples are performed using an optical microscope, scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction technique. It reveals that the nitride layer thickness increases with nitriding temperature. A distinct transition layer between the substrate and nitride layer is observed in the 560 °C and 580 °C nitride samples. The nitriding process develops almost equiaxed grain microstructure with new secondary phase precipitates, whereas in the as-built material, the grains are primarily columnar along the AM process build direction. Specifically, the nitriding process introduces γ-Fe4N, ε-Fe3N, CrN, and Ni3N precipitates. The increase in Ni- and Cu-rich precipitates with the nitriding temperature explains the observed improvement in the hardness and surface roughness. Furthermore, the nitriding process does not alter the substrate's initial weak crystallographic texture.

Performance of corrosion inhibitor extracted from enzymatic hydrolysate of waste Platanus acerifolia leaves

In this study, an ultrasound-assisted enzymatic extraction (UEE) method was proposed to augment the anti-corrosion performance of the green inhibitor extracted from waste Platanus acerifolia leaves. Chemical compositions and anticorrosive properties of UEE extract were characterized via multiple technologies. The adsorption film on the steel surface was characterized via X-ray photoelectron spectroscopy (XPS). The surface information of corroded steel was also analyzed. Results showed that, compared with the ultrasound-assisted alkali extraction (UAE), UEE increased the utilization rate of raw plant materials by 22%∼39%. After optimized via response surface methodology, the maximum yield of UEE extract could reach 27.081 mg/g. Electrochemical results showed, compared with 3% UAE extract, the inhibition efficiency of 3% UEE extract after 72 h in 0.5 M NaCl was increased by 22% while the extraction time was saved by 90%. Microscopic observations also proved that UEE extract can effectively mitigate the corrosion degree where the roughness of steel surface decreased by 63.67%. XPS results revealed that a carbonaceous protecting layer was formed on steel surfaces. The inhibition mechanism analysis suggested that flavonoids and their derivatives were apt to adsorb on the steel surface via chelation and surface physical adsorption, which could block the pathway of chloride attack.