Low Carbon Steel Research Articles

Towards excellent strength-ductility synergy via high temperature short time annealing in low-carbon ultrafine grain steel

A new ar-chitecture of ultrafine grain (UFG) steel with coarsen bimodal size distribution was realized by high-temperature short time annealing process. Abundant comparisons on ferrite size, precipitates, and dislocation were performed with previous works. In the present study, the synthetical mechanical properties showing a tensile strength of 974.9 ± 27.1 MPa and 18.5 ± 1.66% elongation in UFG steel with grain size of 374 nm was enhanced without much strength sacrifice. High-temperature short time annealing process promoted the intragranular Nb(C, N) particles formation and the recrystallization ferrite coarsening. However, the better work hardening ability confirmed by the increased intragranular Nb(C, N) particles dominated the synthetical mechanical properties in UFG steel. The intragranular Nb(C, N) particles advocated the stimulation and accumulation of geometrically necessary dislocations (GNDs), thus the strength increment by work hardening counteracted the decreased strength resulted from coarsen ferrite grains.

Balanced Anti-Corrosion Action of Reduced Graphene Oxide in Zn-Al Coating during Medium-Term Exposure to NaCl Solution

Considering the electronegativity and shielding anti-sepsis characteristic of reduced graphene oxide (G), we design a Zn-Al coating with embedded G (Zn-G/Al) on low-carbon steel using the low-pressure cold spray (LPCS) method. In this method, G-coated Al powders (G/Al) prepared using in situ reduction and Zn powders were mixed as a raw material for spraying. Embedding G could boost the cathodic protection performance of Zn-Al (70 wt.% zinc and 30 wt.% aluminum) coating, as has been confirmed in previous work. In this work, the microstructure, composition and electrochemical parameters of Zn-G/Al coating during full immersion were measured to investigate G’s effect on the corrosion protection properties of the Zn-Al coating. The test results showed that embedded G could facilitate the generation of many corrosion products and pile on the coating surface to form a corrosion product film during full immersion. The corrosion product film on the Zn-0.2 wt.%G/Al coating surface demonstrated an excellent protective property, which reflects the fact that the Ecorr and icorr values for Zn-0.2 wt.%G/Al after 20d immersion (Ecorr = −1.143 Vvs.SCE, icorr= 49.96 μA/cm2) were lower than the initial value (Ecorr = −1.299 Vvs.SCE, icorr = 82.16 μA/cm2). It can be concluded that adding an appropriate amount of G to the coating can balance the cathodic protection and shielding property of the coating. The equilibrium mechanism was also analyzed in this work.

Combining electric discharge surface alloying and high-frequency mechanic impact post-processing for increased corrosion fatigue life of as-welded transverse non-load-carrying attachments of the S355 steel

The combined effects of severe plastic deformation induced by high-frequency mechanical impact (HFMI) treatment and the electric discharge surface alloying (EDSA) with chromium on the corrosion fatigue life of low-carbon S355 steel transverse non-load-carrying specimens are studied in this paper. First, for various alternations of the combined HFMI + EDSA process, the surface alloyed layer integrity and depths were analyzed using scanning electron microscopy (SEM) accompanied with energy dispersive spectroscopy (EDS) and hardness measurements. The alloying and hardening depths were respectively observed to be 10–30 μm and 0.15–0.75 mm and the surface hardness increased up to 3.6–3.9 GPa. Polarization tests demonstrated higher corrosion resistance of the EDSA-processed samples in 3%NaCl. The near-surface layers of the HFMI + EDSA(Cr) + HFMI processed sample characterized by X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) contain the dislocation-cell structure formation and partially dissolved cementite. The fatigue tests in 3%NaCl confirmed that the HFMI + EDSA(Cr) + HFMI post-weld process increased corrosion fatigue life (1.77 × 106 cycles) of the S355 steel welded joint at the stress level of 260 MPa by 2 and 12 times in comparison with the HFMI-treated (0.9 × 106) and as-welded (0.14 × 106) samples, respectively.

Effect of alloying (Cr, Mo, and V) on corrosion behaviors of API-grade steel in CO2-saturated aqueous solutions with different pH

The corrosion behaviors of steels alloyed with Cr, Mo, and V were examined in two different solution chemistries: near-neutral (pH 6) and weakly acidic (pH 4.5) solutions saturated with CO2. In near-neutral solutions, Cr alloying hindered the formation of a stable corrosion scale on the surface, reducing the corrosion resistance compared to conventional low-carbon steel. On the other hand, the alloyed steel exhibited higher corrosion resistance in acidic solutions. In contrast to the conventional carbon steel, which had a single scale of crystalline FeCO3 scale on its surface, a more stable bi-layer of corrosion scale consisting of an inner layer of amorphous Cr(OH)3 and an outer layer of crystalline FeCO3 was developed on the alloyed steel. This was attributed primarily to the increased thermodynamic stability of Cr(OH)3 with an increase in Cr contents at this solution pH. Moreover, the increase in Cr with Mo addition resulted in a refinement of FeCO3 on the outer surface through increased hydrolysis reactions leading to a decrease in the local pH on the steel surface. Furthermore, adding V, even in minute quantities contributed to an increase in Cr-enrichment in the inner scale by suppressing M7C3 precipitation and leaving more Cr in the solid solution.

Low carbon steel corrosion inhibition using environment-friendly Solanum Lycopersicum extract in monoprotic and diprotic acidic medium

The stem extract of Solanum Lycopersicum prepared using the methanol extraction method has been investigated as an environment-friendly inhibitor for low-carbon steel in monoprotic(1N HCl) and diprotic(1N H2SO4) solvents and characterized with FT-IR. A maximal inhibition efficiency of 81.8% in 1 N Hydrochloric acid and 92.92% in 1 N Sulfuric acid is assessed under a certain set of conditions of inhibitor concentration and temperature using weight loss, electrochemical impedance spectroscopy and potentiodynamic polarization. The results present Solanum Lycopersicum extract as a mixed-type inhibitor that predominantly influences the cathodic reaction and followed the Langmuir adsorption isotherm. Reduction in the value of average roughness (Ra)of the surface from 217 nm to 55 nm (in 1 N HCl) and 139.6 nm to 28 nm (in 1 N H2SO4) was observed with AFM after the application of the inhibitor which confirms the formation of a protective membrane and provides green inhibition on the low-carbon steel/solution interface.

Microstructure and Properties of WC-Reinforced Inconel 718 Alloy Cladding Layer by TIG on Low Carbon Steel Surface

Microstructure and Properties of WC-Reinforced Inconel 718 Alloy Cladding Layer by TIG on Low Carbon Steel Surface

Vapor–Gas Deposition of Polymer Coatings on Metals from Azeotropic Solutions of Organosilanes

The mechanism of the vapor–gas deposition of vinyltrimethoxysilane (VS) and ethylene glycol (EG) from azeotropic solutions is investigated, which allows a reduction of the evaporation temperature of the components of working mixtures. The need for such studies is associated with the development of a new direction in the technology of vapor–gas deposition of polymer coatings. Methods have been developed for monitoring the chemical composition of working solutions in evaporators using optical spectroscopy, which makes it possible to calculate the partial pressures of vapor-phase components. Based on these studies, compositions of working solutions are proposed that allow the equalization of the partial pressures of the components of working mixtures with a large difference in the boiling point. With the aid of vapor–gas deposition, siloxane coatings on low-carbon steel were obtained, the protective properties of which exceeded the treatment with volatile inhibitors of the adsorption type by two to three orders of magnitude. A new method of vapor–gas deposition of non-volatile powder inhibitors on metals is proposed. Chemical compositions of siloxane coatings were determined using XPS, and mechanisms of interaction of VS with the polymerization promoters ethylene glycol and 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP) were proposed.

Experimental and DFT Atomistic Insights into the Mechanism of Corrosion Protection of Low-Carbon Steel in an Acidic Medium by Polymethoxyflavones from Citrus Peel Waste

Developing green anticorrosive films is gaining great attention in science and engineering. Citrus fruit peels are mainly discarded as waste, although they can be an excellent repository of phytochemicals, that can be exploited as mitigating agents for corrosion. Herein, we report the high anticorrosion activity of a citrus extract for low-carbon steel in 1 M HCl solution at different temperatures. The main extract constituents were identified by MS and NMR. Two polymethoxyflavones (PMFs), namely nobiletin and heptamethoxyflavone, were identified as major constituents of the extract and the crude PMFs-based extract was investigated for corrosion protection. Using potentiodynamic polarization, weight loss and electrochemical impedance spectroscopy (EIS) methods, this extract revealed improved inhibition efficiency of 94%. The inhibition mechanism was elucidated by considering electrochemical kinetics and adsorption thermodynamics. SEM and UV–vis supported the electrochemical results. PMFs-based extract acted as a mixed-type inhibitor with a Langmuir model of adsorption. Importantly, DFT simulations provided atomic-level insights into the inhibition mechanism and unraveled donor-acceptor interactions between the methoxy groups of PMFs and iron atoms, facilitating the formation of a stable inhibition adsorption layer, and thus supporting the experimental findings. In addition to the physical barrier effect of PMF inhibitor, π-back bonding effect between PMF and steel was suggested.

SAE 1029

Abstract 1029 is a wrought low-carbon (carbon = 0.25–0.31%) non-alloy steel that is used in the normalized, cold worked, or quenched and tempered condition. 1029 may also be nitrided or nitrocarburized. This steel is widely used for small, moderately stressed parts that require higher strength levels than can be achieved by the lower carbon grades, and also for applications where a combination of moderate strength and good toughness is required. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on forming and heat treating. Filing Code: CS-260. Producer or source: Heat Treater's Guide.

Effect of Finish Rolling Temperature on the Texture and Fracture Resistance of Low-Carbon High-Strength Pipe Steels during Thermomechanical Treatment

Effect of Finish Rolling Temperature on the Texture and Fracture Resistance of Low-Carbon High-Strength Pipe Steels during Thermomechanical Treatment

熱間圧延中の低炭素鋼板の酸化皮膜の変形に及ぼすマンガンの影響

In hot rolling process of low carbon steel sheets, oxide scale formed on the sheets may result in surface defects on the rolled products. The major phase of the scale is wustite FeO, which shows sufficient plasticity to follow the sheet deformation only at elevated temperature. However, thick scale is cracked, fragmented and indented to the sheets by the rolling even at elevated temperature because scale surface is instantly cooled by cold rolls to brittle temperature. Therefore, thick scale should be removed by descalers just before the rolling. It is reported that manganese decreases the eutectoid temperature between ductile wustite and brittle magnetite. Therefore, manganese may have a positive effect to widen wustite window to lower temperature and to suppress surface defects. In this study, 0mass% and 2mass% manganese bearing steel sheets with controlled scale on surface were hot rolled in a laboratory. The sheets were reduced 30% in thickness by unlubricated rolling at temperature between 1173 K and 1373 K. Scanning electron microscopy on longitudinal section showed that manganese decreases crack depth and increases spacing between scales indented to the steel. It is concluded manganese makes the scale on steel more ductile and suppresses surface defects.

Long-term corrosion of silicon carbide/enamel composite coatings on steel rebars: A microstructure-dependent corrosion behavior

Steel rebar's corrosion greatly affects the durability of reinforced concrete (RC) structures. Recently, enamel coatings have been developed for steel rebar's corrosion protection. Given that the anticorrosion performance of enamel coatings is strongly related to their microstructure, in this study, pure enamel coating (PE) and three silicon carbide/enamel composite coatings with 2.5, 5, and 7.5 wt.% silicon carbide addition (S2.5, S5, and S7.5) were prepared on low-carbon steel rebars, representing four different microstructure states, which are severely cracked with porosity of 6%, partially cracked with porosity of 17%, slightly cracked with porosity of 20%, and uncracked with porosity of 26%. The long-term corrosion behavior of different coated rebars was investigated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, neutral salt-spray test, and morphological observation to understand the effect of silicon carbide content and coating microstructure on the corrosion behavior. Long-term electrochemical studies (210 days) showed that the Rpor and Rct of S7.5 remained 12 times and 5 times that of PE, respectively, indicating an improved corrosion protection with silicon carbide addition. Combined corrosion studies and microstructure results revealed that the corrosion behavior of enamel coated rebars was closely related to the coating microstructure, especially the pores and microcracks. Furthermore, the competitive mechanism of electrolyte penetration degeneration and “self-healing” like enhancement was proposed to interpret the corrosion evolution modes of different coated rebars. The findings of this work give a deep understanding of the corrosion behavior of silicon carbide/enamel composite coatings and provide a solution for long-life RC structures.

Flow Stress Behavior and Governing Equation of Plastic Flow of Low-Carbon Steel at Elevated Temperatures

Flow Stress Behavior and Governing Equation of Plastic Flow of Low-Carbon Steel at Elevated Temperatures

Laju Korosi Logam Baja Karbon Rendah di Larutan Garam pada Berbagai Konsentrasi Inhibitor Korosi dari Ekstrak Daun Pepaya

Papaya leaf extract could be used as an organic corrosion inhibitor. Corrosion inhibitors were used as a method to reduce corrosion rate. The most corrosive environment was the marine environment. The purpose of this study was to determine the best concentration of papaya (Carica papaya) leaf extract inhibitor which could reduce the corrosion rate of low carbon steel in a 3.56% NaCl solution environment. The maceration process was carried out for 24 hours with 70% ethanol solvent with a solute:solvent ratio of 1:8 (w/v) at room temperature. Inhibitor extracts were analyzed qualitatively with the phytochemical method. The addition of FeCl3 was carried out on the inhibitor extract from papaya leaves. The color change occurred from blackish brown to greenish black which indicated the presence of tannin compounds in the papaya leaf extract. Corrosion testing was carried out with hot stream temperature setting at 45⁰C to 55⁰C and concentrations of inhibitor extracts at 300, 600, and 900 ppm. The test was conducted for 36 hours with a span of metal mass every 6 hours. Corrosion rate calculation is done by weight loss method. The results showed that papaya leaf extract inhibitors positive contained corrosion inhibitor and could reduce the corrosion rate in 3.56% NaCl solution. The corrosion rate without inhibitor is 1.023 mmpy. Corrosion rates with inhibitor concentrations of 300, 600, and 900 ppm were 0.755, 0.585, and 0.438 mmpy, respectively.

Analysis of Tool Wear and Calculation Results of Hardness Values in St 37 Steel Turning Using Characteristics

The development of lathe chisels is currently more advanced with the creation of carbide, CBN, ceramic, and inserts tool types. However, conventional chisel types, one of which is the HSS (high speed steel) chisel, are still used. ST 37 steel is a low carbon steel type that is easy to forge and easy to machine. The level of precision and surface roughness of the resulting workpiece must be in accordance with the needs. The higher the level of surface quality of the workpiece, the higher the level of precision. The research method we use is to find data, then the data obtained is graphed. From the results of the graph it can be concluded that for the depth of cutting the greater the rotation, the greater the depth. For wear, it can be seen that the wear will be greater if the speed is increased. The results of the hardness test at a medium rotational speed of 490 Rpm, the greater the number of examples, the greater the results of the hardness test experienced on the test material.

On obtaining coatings with multimodal roughness on low-carbon steel by thermochemical method

On obtaining coatings with multimodal roughness on low-carbon steel by thermochemical method

Quantification of Retained Austenite in Low-Carbon Steels

Quantification of Retained Austenite in Low-Carbon Steels

Development of roller tank prototypes for moving goods with a capacity of 5 tons

Transporting products is a common practice in many industries. To increase the effectiveness and efficiency of the transfer, assisting devices are utilized. The available goods movement equipment on the market is bulky and less adaptable for moving goods in confined spaces. The primary purpose of roller tanks is to aid and facilitate human labor in the process of moving products from one location to another in order to increase the effectiveness and efficiency of human labor. A roller tank facilitates the transportation of containers, industrial machinery, and other heavy equipment. The purpose of this roller tank's design is to discover: (1) the roller tank's design, (2) the manufacturing process for roller tanks, and (3) the performance test results for roller tanks. Requirements analysis, problem analysis and specifications, design, technical analysis, component fabrication, assembly, and tool testing are the methods used to construct this roller tank. The outcome of this roller tank design is a design with a functional drawing of a roller tank with dimensions of 280 mm in length, 150 mm in width, and 83 mm in height. The roller tank prototype is composed of ST 37 steel plate and low alloy carbon steel. The tank's drive wheel is made of nylon, and its two shaft bearings consist of a ball bearing 6804 ZZ and a roller thrust bearing 55105

An Investigation into the Friction of Cold-Rolled Low-Carbon DC06 Steel Sheets in Sheet Metal Forming Using Radial Basis Function Neural Networks

This article presents the friction test results for cold-rolled low-carbon DC06 steel sheets, which are commonly processed into finished products using sheet metal forming methods. A strip drawing test with flat dies was used in the experimental tests. The strip-drawing test is used to model the friction phenomena in the flange area of the drawpiece. The tests were carried out using a tester that enabled lubrication with a pressurised lubricant. The friction tests were carried out at different nominal pressures, oil pressures, and friction conditions (dry friction and oil lubrication). Oils destined for deep-drawing operations were used as lubricants. Neural networks with radial base functions (RBFs) were used to explore the influence of individual friction parameters on the value of the coefficient of friction (COF). Under lubrication with both oils considered, the value of the COF increased with decreasing oil pressure. This confirms the correctness of the concept of the device for reducing friction in the flange area of the drawpiece. The developed concept of pressurised lubrication is most effective at relatively small nominal pressures of 2–4 MPa. This range of nominal pressures corresponds to the actual nip pressures when forming deep-drawing steel sheets. Under conditions of dry friction, the values obtained for the COF rise above 0.3, while under lubrication conditions, even without pressure-assisted lubrication, the COF does not exceed 0.2. As the nominal pressure increases, the effectiveness of the lubrication exponentially decreases. It was found that the Sq parameter carries the most information regarding the value of the COF. The RBF neural network with nine neurons in the hidden layer (RBF-8-9-1) and containing the Sq parameter as the input was characterised by an R2 of 0.989 and an error of 0.000292 for the testing set.

Friction stir processing: An effective thermo-mechanical processing technique for carbon steels

This review paper deals with the detailed study of published research work on FSW/FSP of different types of steels and post processing such as heat treatment effects on additively manufactured steel beads. In this context, it comprises of post processing effects on steel beads fabricated by additive manufacturing technique that includes different techniques like selective laser melting (SLM), Laser-TIG (Tungsten inert gas), Metal inert gas welding, etc. along with post processing techniques such as hot iso-static pressing (HIP), conventional heat treatment (HT), post weld heat treatment (PWHT), etc. Also, it consists of the pros and cons of FSW/ FSP, especially on low and medium carbon steels. Moreover, this paper is mainly related to the effects of friction stir welding/ processing on the evolution of microstructure, weld morphology, and temperature gradients in the processed region. In addition, there are detailed analyses of tool selection, effect of weld pitch ratio, effect of carbon content (Wt. %), and hard phase volume fraction on yield strength i.e. carbide distribution in the FSP low and medium carbon steels, and their correlation with the mechanical responses as well as crystallographic orientation relationship. Finally, based on published research, gaps are highlighted and presented as future scope of research work.