Rusted Steel Research Articles

Multi-Objective Optimization of Laser Cleaning Quality of Q390 Steel Rust Layer Based on Response Surface Methodology and NSGA-II Algorithm.

To improve the laser cleaning surface quality of rust layers in Q390 steel, a method of determining the optimal cleaning parameters is proposed that is based on response surface methodology and the second-generation non-dominated sorting genetic algorithm (NSGA-II). It involves constructing a mathematical model of the input variables (laser power, cleaning speed, scanning speed, and repetition frequency) and the objective values (surface oxygen content, rust layer removal rate, and surface roughness). The effects of the laser cleaning process parameters on the cleaning surface quality were analyzed in our study, and accordingly, NSGA-II was used to determine the optimal process parameters. The results indicate that the optimal process parameters are as follows: a laser power of 44.99 W, cleaning speed of 174.01 mm/min, scanning speed of 3852.03 mm/s, and repetition frequency of 116 kHz. With these parameters, the surface corrosion is effectively removed, revealing a distinct metal luster and meeting the standard for surface treatment before welding.

The Study of Patterns and Mechanisms of Continuous Laser Ablation of Carbon Steel Rust Layers in Multi-Medium Environments

A new multi-scenario, low-cost, high-efficiency, medium-assisted continuous laser cleaning of corrosion layers was developed. By comparing the roughness and cleaning depth of rust layers cleaned under conditions of liquid-assisted, solid-assisted, and mixed solid–liquid-assisted laser cleaning, simultaneously establishing a three-dimensional finite element model to study the variations during the cleaning process, and conducting a comparative analysis of the results of both, the cleaning mechanism is elucidated. The experimental results indicate that under conditions of water-assisted cleaning, the depth of rust layer increases initially and then decreases with varying water layer heights. The maximum cleaning depth is achieved at a water layer height of 0.1 mm, while the optimal surface roughness occurs at a water layer height of 0.2 mm, indicating a change in cleaning mechanism. The cleaning pattern with SiO2 activator assistance follows a similar trend to a water medium, reaching maximum cleaning depth at 0.1 mm height, with a slight improvement in surface roughness compared to water-assisted cleaning. Finally, solid–liquid mixing can achieve cleaning completion and improve surface roughness under conditions where water-assisted cleaning alone fails to reach a clean state. Therefore, the active agent can be used for laser cleaning to promote the cleaning process, and solid–liquid mixing to assist the laser cleaning can be a theoretical guide for the field of laser cleaning.

A comparative study of the corrosion of Q235 carbon steel in six different strains of marine-isolated sulfate reducing prokaryote

Biocorrosion in marine environments is often associated with biofilms of sulfate reducing prokaryotes. However, the corrosion behaviors of steel differed greatly between the bacterial species. In this study, six strains of sulfate reducing prokaryote including 3 strains of strictly anaerobic bacteria and 3 strains of facultative anaerobic bacteria were isolated from the steel rust immersed in Sanya, China. The corrosion behavior of Q235 carbon steels by isolated six strains was studied by weight loss analysis, electrochemistry measurements, and surface morphology observation. In addition, the relationship between bacterial corrosivity and strain type was investigated. The results indicated that there is no direct relationship between the corrosivity of bacteria and strain type, whether the bacteria were strictly anaerobic or not. The corrosion rates of steel coupons fluctuated with the strain properties and soaking time. Among the strains tested, the strains belonging to Proteobacteria had relatively high corrosion rates on steel coupons, whereas, strain Virgibacillus Dokdonensis of Firmicutes has the lowest corrosion rate. The results provide a guiding basis for exploring the mechanism of microbial corrosion and controlling marine microbial corrosion.

Study of rust layer evolution in Q345 weathering steel utilizing electric resistance probes

In this study, a corrosion-monitoring sensor was used to investigate the evolution mechanism of rust formation on Q345 weathering steel. The results indicate that rust layer formation proceeded through alternating thickening and conversion (no thickening) stages. Specifically, the transformation of Fe2+ to γ-FeOOH increased the thickness of the rust layer in the thickening stages. After each thickening stage, conversion occurred: the composition of the rust layer changed, which entailed an increase in the α-FeOOH content. In the stage of conversion, no thickening occurred and this process was the controlling step of weathering steel rust stabilization.

Research on pulse laser cleaning and rust removal technology in power systems

In this paper, pulse laser cleaning and angle grinder polishing were used to clean the surface rust of carbon steel, and the cleaning effects of different cleaning methods for carbon steel surface rust were studied. The change of the micro-region morphology and element composition of the cleaned surface was analyzed. Comparative experiments were conducted on the corrosion resistance and paint anticorrosion ability of cleaned metal surfaces. Through comparison and analysis, the use of laser cleaning technology can improve the surface cleanliness and corrosion resistance of metals, reduce maintenance times, and extend service life. Laser cleaning machines with a power of 100 W or above can effectively perform precision cleaning and can be widely promoted in the field of power systems.

The Effects of a Multifunctional Rust Inhibitor on the Rust Resistance Mechanism of Carbon Steel and the Properties of Concrete

To address rebar corrosion in existing concrete structures, a multifunctional compound rust inhibitor was developed. This study investigates the impact of this inhibitor on carbon steel rust resistance, as well as the mechanical properties and durability of concrete. The results demonstrate a significant reduction in weight loss of carbon steel when using a multifunctional rust inhibitor, with a rust inhibition efficiency of 82.6%. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to observe and analyze the surface elements of carbon steel, both with and without the presence of a rust inhibitor. The findings indicate that the use of a rust inhibitor leads to a smoother and more stable surface film. The results of the experiments on compressive strength, chloride ion electromobility, and the rapid carbonation test of concrete with varying rust inhibitor contents indicate that increasing the amount of rust inhibitor can improve the compressive performance of concrete and can regulate the mobility of chloride ions. Specifically, when the rust inhibitor content reaches 4%, it has a notable positive impact on the performance of concrete, and further increases in content lead to smoother results.

Corrosion behavior and mechanism analysis of triethanolamine and imidazoline in the simulated pore solution of concrete

In this paper, to solve the previous instability of nitrate rust inhibitors, and their environmental hazards, the rust inhibition performance of green and environmentally friendly triethanolamine and water-soluble imidazoline rust inhibitor was studied under simulated pore solution conditions. The corrosion of steel bars was evaluated by electrochemical and dry-wet cycle tests of carbon steel sheets, and characterization was done by scanning electron microscopy (SEM). Triethanolamine and water-soluble imidazoline rust inhibitors could effectively inhibit the rapid development of carbon steel rust in the composite salt environment. When the dosage ratio was 4:6, the electrochemical impedance of the carbon steel sheet increased, the potential increased, the corrosion current density decreased, the mass loss rate decreased, the surface texture of the carbon steel was clear, and the thickness of the rust product was almost zero. The adsorption mold formed by the organic rust inhibitor made the harmful ions impenetrable, and the rust inhibition effect was optimal.

Geopolymer-based grinding stones utilizable in metal machining

This article presents partial results of a project focused on the Research and development of new grinding tools fixed with hybrid binder based on inorganic polymers. The clay-slag geopolymer with corundum abrasive grains was first time used to prepare novel abrasive tools for metal grinding. The effect of brown and white corundum grains of different grain sizes and content has been investigated. The experiments performed on a rusted steel tube on a lathe along with subsequent scanning electron analysis (SEM) have confirmed the grinding properties of geopolymer grinding stones. The grinding traces detected by SEM analysis correspond to the incorporated amount of the abrasive and the size of the grain used. The results have proven that, in case of metal grinding, a geopolymer matrix can substitute for ceramic binder in grinding tools. The geopolymer grinding stones are an opportunity to sustainable development of a new generation of abrasive materials which utilize waste materials, save primary raw material resources and energy consumption and has a minimum impact on the environment.

Steel rust layers immersed in the South China Sea with a highly corrosive Desulfovibrio strain

Although it is well known that microbes play a significant role in marine corrosion, few studies have systematically studied the relationship between microorganisms and corrosion products under long-term immersion. In this study, the corrosion characteristics of the rust layer formed on carbon steel immersed in the South China Sea for 5.5 years were investigated using various surface analysis and microbial community analysis techniques. Magnetite (Fe3O4), iron sulfide, and green rust were identified in the inner rust layer. The middle rust layer was composed of maghemite (γ-Fe2O3), and some Fe3O4 and mackinamite were also detected. The outer rust layer contained several Fe(III)-oxyhydroxides, and it had a large number of fouling organisms attached to it. In all of the rust layers, anaerobic sulfate-reducing bacteria (SRB) were the dominant bacteria, and they may have played a key role in the formation of the corrosion products. One SRB strain (Desulfovibrio bizertensis SY-1) with a highly corrosivity (13.561 mg/cm2) was isolated from these rust layers, and its physiological and metabolic characteristics were studied. These results expand the membership of corrosive SRB and establish a better understanding of marine microbiologically influenced corrosion (MIC).

Rust Conversion of Proanthocyanidins to Archaeological Steel: A Case Study of Lingzhao Xuan in the Forbidden City.

This work was focused on the rust conversion of proanthocyanidins (PC) for goethite (α-FeOOH), akaganeite (β-FeOOH) and lepidocrocite (γ-FeOOH), trying to show the potential of PC as an eco-friendly corrosion inhibitor and rust converter for archaeological steel conservation. The experiment used a rusted steel screw from Lingzhao Xuan of the Forbidden City in the Qing Dynasty and three kinds of pure iron oxyhydroxides as research samples. By means of micro-Raman, FTIR, XRD, XPS, SEM and EIS, PC had the ability to chemically react with iron oxyhydroxides in the rust, forming amorphous PC-FeOOH with a marked signal about 1384 cm-1 as phenolic-Fe in infrared properties. The original relatively stable iron oxides were not induced to phase transformation and still remained. The converted rust layer could be more stable in the corrosive medium and increased the corrosion potential more effectively. Both the rust layer resistance and the charge transfer resistance of the archaeological samples were improved by at least 3 times with 5.0 g/L of PC, which could reasonably stabilize the archaeological rust and hindered external corrosive penetration into the core. It was a mild protection material that showed satisfactory performance for archaeological steel cultural heritage and has a good application prospect.

Analisis Perkuatan Rangka Atap Baja pada Bangunan Gedung Heritage 1921 Menggunakan Software SAP 2000

Introduction: The roof truss construction used in the cultural heritage building in this analysis is a truss roof truss with 2L angle steel profiles (double elbow) 40.40, 50.50, 60.60, 70.70, IWF steel profile gording 150x150, and roof tile coverings, with a length ofroof 102 m, width 21.6 m, height 5 m, with a distance of 7.4 m and 4.1 m truss. The cultural heritage building discussed in this analysis is the roof, namely the horses. Method: The method used in this study is to collect data in the form of shop drawings. The purpose of the study was to identify the capability of the roof structure with the updated loading regulations RSNI 1727-2018. Results: This analysis uses the latest RSNI 1727-2018 loading regulations and the latest SNI 1729-2015 steel regulations, does not change the installed materials and existing shapes, and does not use earthquake and rain loads, only live/maintenance loads, heavy dead loads. roof coverings, ceilings and hangers, and compressed and suction wind loads. Conclusion: From the resultsof this analysis, it is assumed that the rusted steel profile has been replaced, there are two truss rods that need to be replaced with a 2L 80.80 double angled profile with initial data of a 70.70 2L profile. Analysis of the 3-dimensional roof structure with SAP2000 software by reviewing the dead load, the live load of workers according to the loading regulations of the RSNI 1727-2018, taking into account the compressed wind load of 75.82 m2, the suction wind load of 57.37 m2 according to the wind speed of 40 m/s

Facile fabrication of flower-like γ-Fe2O3 @PPy from iron rust for high-performing asymmetric supercapacitors

Flower-like rust with porous structure can be obtained on the Fe plate by accelerated corrosion in the marine atmosphere. A core-shell structure of γ-Fe2O3 @PPy was developed through annealing and in situ chemical polymerization of pyrrole. The dehydroxylation after annealing enriches the inherent pore structure of rust. The conductive PPy layer with the capacitive properties were found to improve the stability of iron-based anodes while enhancing the charge storage performance. The rust-based composite exhibited superior capacitance performance over the original rust. By matching with a cathode from nickel-cobalt layered double hydroxide (NiCoLDH) based porous Ni network, the asymmetric device delivered a high volumetric energy density of 7.9 mWh cm–3 at a power density of 14.99 mW cm–3, and favorable cycle stability (capacitance retention of 90.1% after 8000 cycles). Most importantly, the energy storage mechanism of rust-based electrodes with flower-like structures was discussed in detail. The recycling and reuse of rust resources were successfully realized by the direct utilization of rusted steel as anode materials for supercapacitor applications.

Investigation on ion selectivity of low-alloy steel rust layers produced in industrial and non-industrial marine environment

In this work, we investigated the behavior of rust layers produced from low-alloy steel in marine splash environments, revealing that the above (double) layers were easy to peel off and demonstrating the occurrence of internal anion enrichment and external cation enrichment. In an industrial environment, competition between S-containing and chloride anions was observed inside the rust layer, with the former exhibiting a larger influence. The ion selectivity of the peeled rust layer was modeled using an ion barrier coefficient (P) as Ψ=RTFPlnc2c1, with the decrease of P in an industrial environment and the corresponding increase in a non-industrial environment implying decreased and increased cation selectivities of the rust layer, respectively. Finally, sulfate regeneration was shown to make the industrial environment–exposed rust layer uneven, precluding it from exhibiting stable cation selectivity.

Seven Names for Light

Seven Names for Light Marc Labriola (bio) Click for larger view View full resolution A woman gives birth in a room where all the windows are covered with pages of a book to be burned. The woman inside, the women outside: all wait for the author. Luz is going to scream. She can't drag her body any closer to the bed, so it will happen where she fell. There is a sound she thinks has come from her. Down her thighs she feels something she knows is not what it feels like. Now a faint odor of semen. Her black hair is dripping. The lights shut off again. There have been rolling blackouts since the night it happened. She's covered all the windows of her third-floor apartment with pages from the book they will eventually burn. She can't let the women see her. Luz pulls off her towel. Her eyes haven't adjusted to the dark. Between her legs little drops slowly cool into glass eyes on the tiles. The blood on the floor would have been red. [End Page 14] There is a shock in her waist. Her body jumps like falling in her sleep. This is her first so Luz doesn't know what hurts when. She can't get to her phone. Her heels slip as she pushes back towards the bed. The water on the floor isn't water. Luz can't breathe anymore. They tell you to breathe. Just make it to the bed. She can't let the women hear her. Luz gropes around the dark floor for something to put in her mouth. Her apartment is half empty now. Just the things that survived. She can still see the rusted steel bars like fossilized ribs where seven months ago pieces of the concrete ceiling collapsed in the earthquake. She bites down on her lip until she can taste it. If this were a dream it would be a symbol of something. It wasn't hard for them to find her. He never should have used the real names of the streets in the novel. They won't leave her alone now they know the father is Gabriel Luria. Her apartment has already been broken into three times. Looted for charms or souvenirs. They took coins, earrings, forks and knives, her lipstick, hairbrush. Anything she touched. Even pulled the sheets off her bed. Luz doesn't want this to happen here. Those strange women waiting in the street. It's too soon. She has six days' clothes packed in the suitcase on her bed. But Luz is one week early. She shuts her eyes tight and mouths her list of baby names that mean colours. Her favourite boy's name means red. This is when Luz screams. Someone outside must have heard the voice of a woman through the wall screaming God. But she knows that at a certain distance she is not a woman screaming. She is just a sound someone thought they heard. Blamed on other things. If you're far enough away, even the worst earthquake in living memory is just a little fetal kick. She listens. No one is coming. She knocks the candle and lighter off the table with the tips of her fingers. Flicks the wheel and it lights. In the book, Gabriel says to her, with your clothes off, I count seven different colours. He says the blue blood in the veins on your legs is not really blue. It's just the behaviour of light coming and going from your skin. Of everything we don't know we mostly don't know about light. Luz bites down hard on the back of her hand. Trying to siphon the pain. Don't let them hear. Day and night they're out there with their dog-eared copies of the book, famous around the world because the day the earthquake happened was the same day the novel said it would happen. The book says a comet from the genitals of the constellation Leo entered the womb of the constellation Virgo in a celestial insemination on exactly the night of July 17, the night of...

Microbiologically influenced corrosion of steel in coastal surface seawater contaminated by crude oil

Petroleum-hydrocarbons spilt in surface seawater may pose potential threats to the corrosion of steel infrastructures. We show that crude oil accelerated steel corrosion mainly by accelerating microbiologically influenced corrosion (MIC). Crude oil led to the dominance of marine oil-degraders including Alcanivorax and Marinobacter in both seawater and steel rust, rather than sulfate-reducing bacteria (SRB) which dominated the rust microbial community in the no-oil group. Crude oil not only enhanced microbial oxygen respiration and aerobic hydrocarbon degradation but also nitrate reduction and anaerobic hydrocarbon degradation process in steel rust, indicating more heterogeneous microenvironments formed on steel surfaces. Furthermore, the low abundance of SRB and dissimilatory sulfate reduction gene (dsr), and the existence of iron-carbonate and iron-sulfate minerals implied that microbial sulfide, previously regarded as the main cause of MIC, was not the major contributor to steel corrosion in early petroleum-polluted seawater. Marine specialized oil-degraders seem to play more significant roles under such conditions.

Bonding Mechanism of Zonal Isolation Materials to Clean and Rusted Casing

Summary In oil and gas and geothermal well construction, a cementitious material is pumped in the wellbore to provide zonal isolation and support the casing during the life cycle of the well. Thus, the cementitious barrier materials must be durable in terms of chemical and mechanical properties and have chemical compatibility with casing pipe. The complex region of casing-cement interface is considered a key parameter to fulfill long-term zonal isolation. This interface must be chemically stable and impermeable to block unwanted formation fluid communication. Shortcomings of conventional Portland cement under operational conditions and increasing sensitivity to its carbon footprint are motivations for a green alternative. Bond strength and sealability of cement with steel surface have been measured previously. But few research works cover surface characterization and morphological analysis of barrier materials and the connected steel surface. This study provides a full picture of selected alternative materials in terms of shear bond strength, hydraulic sealability, and interface morphology analysis of the materials. Materials include API Class G cement, an industrial expansive cement, noncement-based pozzolanic material, geopolymer, and thermosetting resin. Also, clean and rusted steels were considered as a representative for the casing pipe in the field. The samples were prepared under elevated pressure and temperature. The results proved that higher shear bond strength is not an indication of good sealability, and the ingredients used to mix slurries have a critical role in the structure of the interfacial zone between casing and barrier material.

The rusted steel that binds: how craft producers form neolocal economies in Pittsburgh, PA

ABSTRACT As many post-industrial cities shift to service and information, manufacturing legacies – material and symbolic – persist in diverse ways. The “Steel City” of Pittsburgh, Pennsylvania exemplifies both deindustrial transition to “eds and meds” and vibrant small-scale production. Cultural geographers interpret place-based craft production as neolocalism, while economic geographers emphasize ways craft can be embedded in evolving economic regions. To understand how local craft production is situated within economic and urban change, this project asks: How do craft producers work – individually and collaboratively – to produce neolocal economies in formerly industrial Pittsburgh? Semi-structured interviews, workshop tours, and a mapping exercise with twenty craft producers and suppliers explored the nature of small-scale production, its embeddedness in place, and professional and supplier networking. The research reveals ways craft workers, suppliers, and organizations in Pittsburgh self-consciously adapt social and material legacies of manufacturing, cluster in particular neighborhoods, and network to build local supply chains and communities. While producers are unevenly engaged in industrial legacies and economies and bound up in wider processes like gentrification, craft labor and collaboration can help maintain traditions of production in places once defined by them.

Corrosion Behavior of Weathering Steels with Different Contents of Rare Earth Elements La and Ce

The effects of different contents of rare earth (RE) elements Ce and La on the corrosion behavior of weathering steel Q355NHq were investigated with alternate immersion tests and electrochemical measurements. The corrosion rates were lowest with the rusted steels containing 170 ppm RE elements. Aspex analysis showed that steels with the RE elements content of 170 ppm had the greatest percentage of inclusions with high content of RE elements. The immersion tests showed that modified inclusions with a high percentage of (RE)xOy exhibited a better corrosion resistance than CaS-Al2O3 inclusion. Compared with steels containing no more than 90 ppm RE, the rust layers of steels containing 170 ppm RE elements were compact and contained high amounts of α-FeOOH and low amounts of γ-FeOOH. Based on the results obtained, the influence of the different contents of RE elements in weathering steel corrosion is discussed.

Understanding in compositional phases of carbon steel rust layer with a long-term atmospheric exposure

Available research mainly hold opinion that the rust layer on plain carbon steels under atmospheric condition contains a higher amount of γ-FeOOH, but that on weathering steels contains a large amount of α-FeOOH. However, the performed investigations were almost done in a short exposure duration with no more than 15 years. In this work, the compositional phases of rust layer on plain carbon steel exposed to an indoor atmosphere for about 40 years have been characterized. Interestingly, α-FeOOH has been identified as the main phase, indicating that α-FeOOH can also be the dominant phase of rust layer even for plain carbon steel after a long-term atmospheric exposure.

Can hypochlorous acid be a powerful sanitizer to replace alcohol for disinfection ? -Its bactericidal, degradation of the solutions under various storage condition, and steel rust effects.

Coronavirus disease pandemic has led to a shortage of disinfectant alcohol (DA; 76.9-81.4% ethanol solution) in Japan. This study investigated the availability of hypochlorous acid (HA) as an alternative disinfectant to DA in clinical environment. HA is a safe and economical disinfectant with a broad antibacterial spectrum and low risk of hand irritation, which is used worldwide. In this study, HA and sodium hypochlorite solution (SH) were degraded over time and the degradation was accelerated by temperature and lighting. Results of bactericidal effects of HA revealed that the realistic effective concentration should be 200 ppm. Compared with DA, the dental carbon steel burs were more severely rusted by SH and HA. These results indicated that high concentration of HA generated on-site could be an effective and safe disinfectant for use immediately after generation with consideration of object materials in clinical environment, as an alternative to DA.