Steel Surface Research Articles

Resilient machine learning for steel surface defect detection based on lightweight convolution

AbstractSteel, as a crucial material extensively used in various fields, has a critical impact on the determination of the stability and reliability of engineering structures. Nevertheless, because of inevitable factors in manufacturing, transportation, and other processes, steel may exhibit various surface defects during production and handling. To address these defects, the investigation puts forward a resilient machine-learning method for steel surface defect detection based on lightweight convolution. First, to reduce redundant features, complexity, and computational cost, the Spatial and Channel Reconstruction Convolution (ScConv) module is added before the Spatial Pyramid Pooling-Fast (SPPF) within the YOLOv8n’s backbone network. Second, in the Neck layer, lightweight convolution GSConv is used to replace the convolutional modules, and the efficient cross-stage partial network (CSP) module, VoV-GSCSP is substituted for the C2f module to alleviate the model burden while maintaining accuracy. Then, to focus on important information related to the current task, the Coordinate Attention module is added to the Neck layer. Finally, the activation function of YOLOv8n has been swapped for the Leaky Rectified Linear Unit (LeakyReLU) to effectively address issues such as gradient vanishing and overfitting. The method achieved a mean Average Precision (mAP) of 77.7% on the NEU-DET dataset, which is an improvement of 4.7% over the original YOLOv8n. Additionally, the frames per second (FPS) reached 17.36 f/s, representing a 5.79 f/s increase compared to the original YOLOv8n. On the GC10-DET dataset, mAP improves by 5.5%, with a FPS of 15.63 f/s. A plethora of experimentation on both datasets illustrates the method’s robustness, meeting the precision criteria for detecting metal defects.

Research on the corrosion mechanism of Q345R steel under water-oil two-phase flow with the HCl and NH4Cl corrosive medium in low-temperature system of petrochemical plants

The serious corrosion failure phenomenon of HCl and NH4Cl in the water-oil two-phase flow are usually occurred in the low-temperature system of petroleum refinery facilities. In this paper, the corrosion mechanism of these corrosive medium in two-phase flow environment was investigated in detail by using corrosion weight loss, electrochemical measurement methods, surface analysis techniques, and numerical research methods. The results indicate that the corrosion rate of Q345R steel in an HCl-NH4Cl coupling medium falls between the rates observed with each medium alone. The stirring of the corrosive fluid creates an unstable oil-in-water emulsion. The formation of an oil film on the surface of Q345R steel slows down the corrosion process and alters the surface corrosion morphology when the oil phase was not originally present. Increasing the proportion of the water phase accelerates the corrosion rate, and the stronger wettability of the oil phase makes the loose γ-FeOOH products easier to cover the surface, which can effectively prevent the mass transfer and corrosion reaction process.

TiC-Reinforced Austenitic Stainless Steel Laser Cladding Layer on 27SiMn Steel Surface: A Comparative Study of Microstructure, Corrosion, Hardness, and Wear Performance

TiC-Reinforced Austenitic Stainless Steel Laser Cladding Layer on 27SiMn Steel Surface: A Comparative Study of Microstructure, Corrosion, Hardness, and Wear Performance

Analysis of the process behaviour of diamond-coated foams in finishing of ground hardened steel

To broaden the process understanding with regard to a tool concept for finishing operations based on soft foams coated with diamonds, the application behaviour with respect to the surface preparation of a ground hardened steel surface is considered. By analysing the surface on the basis of established roughness parameters, the material removal behaviour is investigated in dependence on the process parameters and tool specifications. Furthermore, the influence on the micro roughness superimposed on the roughness profile can be analysed. The recorded process forces serve as a basis for understanding the underlying mechanisms and for interpreting the results.

Evaluation of Magnetron Sputtered TiAlSiN-Based Thin Films as Protective Coatings for Tool Steel Surfaces

Evaluation of Magnetron Sputtered TiAlSiN-Based Thin Films as Protective Coatings for Tool Steel Surfaces

Development and application of a bacteriophage cocktail for Shigella flexneri biofilm inhibition on the stainless steel surface

Food contamination and biofilm formation by Shigella in food processing facilities are major causes of acute gastrointestinal infection and mortality in humans. Bacteriophages (phages) are promising alternatives to antibiotics in controlling plankton and biofilms in food matrices. This study isolated two novel phages, S2_01 and S2_02, with lytic activity against various Shigella spp. From sewage samples. Transmission electron microscopy revealed that phages S2_01 and S2_02 belonged to the Caudovirales order. On characterizing their lytic ability, phage S2_01 initially exhibited relatively weak antibacterial activity, while phage S2_02 initially displayed rapid antibacterial activity after phage application. A combination of these phages in a 1:9 ratio was selected, as it has been suggested to elicit the most rapid and sustained lysis ability for up to 24 h. It demonstrated lytic activity against various foodborne pathogens, including six Shigella spp. The phage cocktail exhibited biofilm inhibition and disruption abilities of approximately 79.29% and 42.55%, respectively, after 24 h in a 96-well microplate. In addition, inhibition (up to 23.42%) and disruption (up to 19.89%) abilities were also observed on stainless steel surfaces, and plankton growth was also significantly suppressed. Therefore, the phage cocktail formulated in this study displays great potential as a biological control agent in improving food safety against biofilms and plankton.

Ageing of commercial austenitic, martensitic and duplex stainless steel surfaces after formation of laser-induced periodic surface structures by fs-laser irradiation

The time-dependent wetting behavior was investigated for commercially available austenitic, martensitic and duplex stainless steel surfaces after femtosecond (fs) laser irradiation. For this purpose, highly regular LIPSS with almost identical geometric properties were generated on the stainless steels in an air environment by near-infrared fs-laser processing (λ = 1025 nm, τ = 300 fs, frep = 100 kHz, v = 0.67 m/s, Δx = 6 μm, F = 1.1 J/cm2) and compared to the polished initial surfaces as reference. The wetting with distilled water was evaluated as a function of aging time by contact angle measurements using the sessile drop method. The laser-induced morphological, topographical and chemical alteration of the surface was characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, glow-discharge optical emission spectroscopy as well as high-resolution imaging and scanning transmission electron microscopy. Despite an almost identical LIPSS-based topography alteration, the stainless steels revealed very different ageing behavior. For permanently used samples, it was shown that the ageing effect is less pronounced than for samples that were stored in ambient air following fs-laser irradiation until the wetting measurement. The results obtained make an important contribution to understanding and controlling the ageing effect of metal surfaces and thus facilitate the transfer of LIPSS-based functional surface engineering and design to industrial processes.

Achieving a super-strengthening functional composite coating from ZnO doped snail shell particulate for mitigation of mild steel towards improved microstructural, corrosion, and opto-electrical properties

Long-lasting protective coatings are essential, particularly under harsh operating conditions. Surface coatings provide a flexible alternative; electrodeposition is becoming an established approach for protecting steel. The intent of this study is to determine how effectively zinc oxide (ZnO) coatings for mild steel corrosion protection effect when integrated with snail shell particle (SSP). The experimental setup consisted of producing a coating bath with ZnO and SSP particles, then electrodeposting the mixture under conditions onto polished steel surfaces. The created coatings were subjected to an array of tests, including electrical conductivity and resistivity testing, morphological analysis using SEM/EDS, corrosion testing in a 1M HCl solution, hardness testing. The findings show that when SSP content increases, steel corrosion rates significantly decrease, suggesting improved corrosion resistance from 21.85(mm/yr) to 12.80(mm/yr), and polarization resistance of 4.47E+01(Ω) to 8.00E+01(Ω). Morphological examination shows that SSP particles are dispersed throughout the coating matrix, which promotes adhesion and stability. Also, coatings with more SSP show better electrical characteristics. Overall, the study shows how ZnO-SSP coatings can shield mild steel components from adverse conditions and have prospective uses in sectors where surfaces resistant to corrosion are needed.

Zr-based conversion film fabricated on cold rolled steel by separately providing zirconium and fluorine ions: Performance and mechanism study

Controlling the concentrations of Zr4+ and F− in traditional Zirconium (Zr)-based film-formation solution is challenging due to their dependence on the hydrolytic equilibrium of H2ZrF6. In this study, Zr-based films were prepared on cold rolled steel surface through the film-formation solution prepared by mixing Zr(NO3)4 and different amount of HF. The electrochemical results demonstrated that the Zr-based film prepared by Zr(NO3)4 and HF exhibited superior corrosion resistance compared to H2ZrF6. Under optimal film formation conditions, the protective efficiency of the prepared film reached 74.4 % which was higher than that of film fabricated in H2ZrF6. The electrochemical results concurrently demonstrated the self-reinforcing anti-corrosion performance of the prepared films. Scanning electron microscopy revealed that the Zr film, prepared in Zr(NO3)4 and HF, exhibited excellent corrosion resistance attributed to its high film density. The X-ray photoelectron spectroscopy and energy dispersive spectroscopic results indicated the presence of a fluoride layer on the surface of the Zr film. The F− ions can chelate with the corrosion products and selectively deposit onto the damaged areas of the film, thereby effectively contributing to the repair of the film layer. The results of density functional theory calculations demonstrated that Zr4+ readily forms Zr(OH)4 rather than ZrF62−. The present study offers an enhanced approach for regulating the properties of films prepared via H2ZrF6 by separately providing zirconium and fluorine ions.

An electrochemical and theoretical approach towards the efficient microwave synthesis of imidazolium-based ionic liquids for unprecedented mild steel corrosion inhibition in 0.5 M H2SO4 solution

The inhibition potential of newly synthesized imidazolium-based ionic liquids (IL-1 and IL-2) on mild steel corrosion in a 0.5 M H2SO4 solution has been comprehensively investigated using gravimetric analysis, potentiodynamic polarization, and electrochemical impedance spectroscopy across various temperatures. Gravimetric analysis indicated that the adsorption of these inhibitors adhered to the Langmuir adsorption isotherm. Significantly, IL-2, featuring a longer alkyl chain, demonstrated superior inhibition efficiency (92.51 % at 303 K) compared to IL-1 (88.71 % at 303 K). Potentiodynamic polarization studies revealed a mixed-type inhibitory behavior, impacting both anodic and cathodic reactions. Surface morphological analyses via SEM and EDX confirmed the formation of a protective film on the mild steel surfaces, substantiating the corrosion inhibition capabilities of IL-1 and IL-2. The novelty of this research lies in the application of density functional theory (DFT) using the B3LYP method, which elucidated that the alkyl chain length at the N-3 position in imidazolium cation-based ionic liquids significantly enhances their inhibition potential. This mechanistic insight suggests that these ionic liquids effectively obstruct both anodic and cathodic sites, providing robust corrosion protection in a 0.5 M H2SO4 solution.

Effect of the Laser Cladding Parameters on Microstructure and Elevated Temperature Wear of FeCrNiTiZr Coatings.

In order to prepare coating with good friction and wear resistance at elevated temperature on the surface of hot-working tool steel, by using a CO2 laser, FeCrNiTiZr high-entropy alloy coating with different laser scanning speeds (360, 480 and 600 mm/min, respectively) was successfully fabricated by using laser cladding technology on the surface of H13 steel in this paper. Phase constitutions, microhardness, microstructure, and wear characteristics of FeCrNiTiZr coatings under different laser scanning speeds were analyzed. It was determined that 480 mm/min was the optimal laser scanning speed. The results showed that the coating at the scanning speed of 480 mm/min consists of a BCC phase with significant lattice distortion and high dislocation density; the crystal structure is cellular crystal and dendrite crystal. The coating demonstrates the highest microhardness (842 HV0.2), which is 4.2 times that of the substrate (200 HV0.2). Its average friction coefficients at room temperature and 823 K are approximately one-seventh and one-third of the substrate's, respectively, and its wear volume is reduced by about 98% and 81% under these conditions. Compared to the substrate, the coating underwent slight abrasive wear, adhesive wear, and oxidative wear at both room temperature and 823 K. In contrast, the substrate underwent severe abrasive wear, adhesive wear, oxidative wear, and even fatigue wear.

Electrochemical, thermodynamic and DFT studies of Fomitopsis pinicola as green corrosion inhibitor for carbon steel in sulfuric acid

In this work, the methanolic extract of Fomitopsis pinicola has been evaluated as a green corrosion inhibitor for the dissolution of 1018 carbon steel in 0.5 M sulfuric acid. For this, gravimetric tests and electrochemical methods such as potentiodynamic polarization curves, linear polarization resistance (LPR) and Electrochemical Impedance Spectroscopy (EIS) techniques were used. These tests were aided with Infrared and GC–MS analytical techniques. In addition to this, theoretical calculation with the use of the density functional theory (DFT) technique has been used to correlate the electronic extract properties and its inhibitory capacity. Weight loss results have shown an inhibitor efficiency of 85 % with the addition of 400 ppm. Thermodynamic parameters have shown that Fomitopsis pinicola extract is physically adsorbed onto the steel following a Langmuir adsorption isotherm. Potentiodynamic polarization curves showed that the extract behaves as a mixed type of corrosion inhibitor inducing the formation of a protective film onto the steel surface. In the presence of the Fomitopsis pinicola extract, a more resistive film obtained the highest polarization resistance value when 400 ppm of extract was used. In addition to this, as the concentration of the extract increased the charge transfer resistance and the double electrochemical layer capacitance decreased. GC–MS results indicated that main compounds contained in the Fomitopsis pinicola extract were Dehydrergosterol, Hydrazino-acetic acid ethyl ester, and Phthalic acid, di (2-propylpentyl) ester, whereas theoretical calculations showed that the highest EHOMO and lowest ELUMO values correspond to Dehydrergosterol and the Phthalic acid, which are the responsible for the extract inhibitory properties.

Effects of rare earth modifying inclusions on the nucleation mechanism and mechanical properties of MC5 roller steel

The effect of Ce treatment on the inclusions and mechanical properties of MC5 roller steel after solidification and annealing process was investigated. The implementation was observed by thermodynamic calculation, Electron Probe Micro-Analyzer and high-temperature confocal laser scanning microscopy (HT-CLSM). The results showed that as rare earth content increase, the inclusions were effectively modified into cerium oxide (Ce-O) and cerium sulfide (Ce-O-S); Compared with 0 RE steel, eliminating the proportion of inclusions larger than 5 μm by 14% and 22%; the average size decreased to 3.60 μm and 2.30 μm. Subsequently. CLSM was used to observe the aggregation, separation and agglomeration behavior of MgAlO4 inclusions and alloy elements on the surface of molten steel. Moreover. the ultimate tensile strength and yield strength of MC5 roller steel with Ce treatment increased by 12.6% and 34%. The addition of rare earths could improve the of MC5 roller steel, it provides effective reference value for subsequent industrial experiments.

A Global Feature Reused Network for Defect Detection in Steel Images

Abstract Accurate detection of surface defects for steel is essential to improve surface quality and service life. Deep learning (DL) used in steel surface defect detection can solve the problems of low efficiency and poor accuracy of traditional manual detection. The classic YOLOv5 as a DL method is used to accomplish defect detection tasks without attention mechanisms, resulting in a loss of global information. Besides, it is difficult to complete complex network detection tasks with low-configuration hardware, especially for surface defects with complex defect types and variable defect sizes. To solve these issues, this paper introduces an improved global feature reuse and hardware-aware YOLOv5 by using BoTNet, RepGhost, and EfficientRep model (BGE-YOLOv5). The multi-head self-attention layer is used to obtain global information and only part of the convolutional layers is replaced to avoid the excessive computational cost. The RepGhost model is introduced to extract the remaining feature information for feature reuse. EfficientRep is used to replace the original structure to achieve hardware-aware and to balance the detection veracity and efficiency. The distance IOU is replaced by SCYLLA-IOU to accelerate the iteration and improve stability. The results of the framework on the surface defect database (NEU-DET) show that BGE-YOLOv5 achieves a mean average precision of 79.5%, which is 10.3% greater than the baseline. The proposed BGE-YOLOv5 has a better performance in steel surface defect detection.

Research on the Detection of Steel Plate Defects Based on SimAM and Twin-NMF Transfer

Pulsed eddy current thermography can detect surface or subsurface defects in steel, but in the process of combining deep learning, it is expensive and inefficient to build a complete sample of defects due to the complexity of the actual industrial environment. Consequently, this study proposes a transfer learning method based on Twin-NMF and combines it with the SimAM attention mechanism to enhance the detection accuracy of the target domain task. First, to address the domain differences between the target domain task and the source domain samples, this study introduces a Twin-NMF transfer method. This approach reconstructs the feature space of both the source and target domains using twin non-negative matrix factorization and employs cosine similarity to measure the correlation between the features of these two domains. Secondly, this study integrates a parameter-free SimAM into the neck of the YOLOv8 model to enhance its capabilities in extracting and classifying steel surface defects, as well as to alleviate the precision collapse phenomenon associated with multi-scale defect recognition. The experimental results show that the proposed Twin-NMF model with SimAM improves the detection accuracy of steel surface defects. Taking NEU-DET and GC10-DET as source domains, respectively, in the ECTI dataset, mAP@0.5 reaches 99.3% and 99.2%, and the detection accuracy reaches 98% and 98.5%.

Oxidized textured stainless steel surface with passivation layer as a high temperature selective solar absorber

A nanocrystalline textured stainless steel (SS) surface passivated with an AlCr oxide layer is proposed for use as a high temperature solar selective absorbers (SSAs). The textured SS surface was prepared by oxidizing in air at 800 °C for 30 min. The heating resulted in outward diffusion of the SS substrate Mn atoms, their oxidation on the surface, and formation of octahedral Mn3O4 nanocrystals, which play a role of textured surface. The passivation AlCr oxide single layer was deposited on the textured surface using reactive RF magnetron sputtering to protect the SS from further oxidation. The solar absorptivity αs and thermal emissivity ε298K of the as-deposited SSAs were 0.84 and 0.165, respectively. In order to study high temperature stability, SSAs were heat treated under air conditions at 600–900 °C for 0.1–300 h. SSAs demonstrated thermal stability at 600 °C for at least 300 h and degradation of optical properties with performance criterion PC < 0.05 at 700, 800, and 900 °C for 300 h, 30 h, and 1 h, respectively. The increase in thickness of the surface Cr2O3 layer on SS substrate was identified as the main degradation mechanism of SSA optical performance. SSAs demonstrated a high activation energy of 330 ± 30 kJ/mol. The obtained data can be used to design high temperature SSAs for concentrating solar energy systems operating under vacuum or air conditions at 500 °C.

Corrosion behaviour of 110SS steel in hydrochloric acid and blended acid system at 200°C

The influence of organic acids (formic acid, acetic acid) on the corrosion behaviour of 110SS steel, a hydrogen sulphide corrosion resistant alloy steel, in hydrochloric (HCl) acid environments was studied. The corrosion rates of 110SS steels in HCl acid and blended acid were measured using the high-temperature and high-pressure corrosion tester. Scanning electron microscopy was utilised to observe the morphology of corrosion products on steel samples corroded by different acid systems, and the energy dispersive X-ray spectrometer was used to analyse the elemental composition of the corrosion products. The corrosion morphology was observed using a 3D laser scanner. The results indicated that the corrosion rate of 110SS steel in HCl acid at 200 °C was an exponential function of HCl concentration. Reducing the HCl concentration significantly decreased the corrosion rate of 110SS steel. Organic acids and corrosion inhibitors synergistically reduced the corrosion of 110SS steel in HCl acid. Adding 3 wt.% organic acid to the 15 wt.% HCl acid system further reduced the corrosion rate, with a more pronounced effect observed in the HCl–formic acid system compared to the HCl–acetic acid system. Organic acids chemically adsorbed onto the steel surface and decomposed to produce CO, which hindered the attack of hydrogen ions on the metal. The added corrosion inhibitor and intensifier Sb2O3 resulted in the formation of a compact adsorption film on the steel surface, further inhibiting corrosion. The optimal mass ratio of HCl acid to organic acid was found to be 15% to 3%.

Electrochemical behavior of mild steel coated with long alkyl-chain benzothiazole derivatives in acid solution: Effect of aliphatic chain length

Mild steel surfaces were coated with four different benzothiazole derivatives with long alkyl chain, namely 2-(heptyl)-benzothiazole (HEBT), 2-(tridecyl)-benzothiazole (TDBT), 2- (pentadecyl)-benzothiazole (PDBT), and 2-(heptadec-8-en-1-yl)benzothiazole (HDBT) from their respective chloroform solutions. Electrochemical experiments were conducted with coated and uncoated mild steel samples exposed to 1 M aqueous HCl at temperatures between 20°C to 50°C and at different immersion times from 6 h to 48 h. TDBT behaves as the best corrosion inhibitor among the four (more than 99 % efficiency at 40°C) and the order of inhibition efficiency follows the trend: TDBT>HDBT>PDBT>HEBT. This reflects the inhibition efficiency to increase with chain length initially, but decreases after a threshold. HDBT, in-spite of having longest aliphatic chain, exhibits better inhibitory performance over PDBT. This is attributed to the presence of unsaturation in HDBT. TDBT coating maintains high corrosion inhibition efficiency even after the 24 h of exposure (above 98 %). Occurrence of spatial hindrance during adsorption of BT derivatives with long aliphatic chain has been manifested by MD simulation.

Microstructural and mechanical characterization of chromium carbide layers obtained on 100Cr6 and X200Cr12 steels by conversion

Carbides and Nitrides of transition metals are widely used due to their interesting properties. Several deposition methods and techniques can be used to produce carbide and nitride coatings. The choice of how to make the deposit depends on several parameters such as, the conditions of use of these deposits, the thickness to be produced, the adhesion between the substrate the deposit, and the cost. In this work, hard coatings of chromium carbide were produced by a conversion treatment on 100Cr6 and X200Cr12 steels. The conversion treatment consists of electrode position of chromium on the surface of 100Cr6 and X200Cr12 steels followed by diffusion annealing treatment at 1000 and 1100 °C for holding times of 1 and 2 hours. The obtained results show that, for all the conversion treatments carried out in this work, there was formation of chromium carbides layer on the surface of steel. However, it should be noted that the nature of the constituting phases of the formed layer depends on the temperature of the diffusion annealing treatment and the duration at this temperature. It should also be noted that the X-ray diffraction analysis has allowed us to show the existence of chromium oxide in addition to chromium carbides. The microhardness profile and the scratch test show that the X200Cr12 steel sample shows better results.These properties are usually obtained by expensive methods such as PVD, CVD, while we can obtain them by easy and inexpensive methods.

Synergistic effects of mixed microorganisms on the corrosion of X65 carbon steel in actual reinjection water

Complex microbiological interactions in reinjection water can lead to severe corrosion of pipelines. In this study, X65 specimen was used for corrosion simulation experiments to explore the microbiologically influenced corrosion (MIC) and mechanism in actual oilfield reinjection water. The results of scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) showed that the X65 carbon steel was severely corroded by microorganisms, with the maximum localized corrosion pit depth of 15.04 μm after 28 days of immersion. Electrochemical analysis and weight loss measurement further confirmed that the mixed microorganisms caused serious corrosion of X65 carbon steel, and the maximum corrosion rate was 0.249 mm/y. Furthermore, microbial community structure determination showed that mixed microorganisms in the actual reinjection water formed a corrosive biofilm on the surface of X65 steel, inducing severe pitting corrosion, which was mainly attributed to the synergistic effect of Pseudomonas, sulfur-oxidizing bacteria (SOB), sulfate-reducing bacteria (SRB) and methanogenic archaea. The results of this study have important guiding significance for the identification of MIC process for actual water samples of the oilfield and the timely adjustment of MIC control measures.