Carbon Steel Specimens Research Articles

Electrochemical Corrosion of Galvanized Steel in Binary Sustainable Concrete Made with Sugar Cane Bagasse Ash (SCBA) and Silica Fume (SF) Exposed to Sulfates

This research evaluates the behavior corrosion of galvanized steel (GS) and AISI 1018 carbon steel (CS) embedded in conventional concrete (CC) made with 100% CPC 30R and two binary sustainable concretes (BSC1 and BSC2) made with sugar cane bagasse ash (SCBA) and silica fume (SF), respectively, after 300 days of exposure to 3.5 wt.% MgSO4 solution as aggressive medium. Electrochemical techniques were applied to monitor corrosion potential (Ecorr) according to ASTM C-876-15 and linear polarization resistance (LPR) according to ASTM G59 for determining corrosion current density (icorr). Ecorr and icorr results indicate after more than 300 days of exposure to the sulfate environment (3.5 wt.% MgSO4 solution), that the CS specimens embedded in BSC1 and BSC2 presented greater protection against corrosion in 3.5 wt.% MgSO4 than the specimens embedded in CC. It was also shown that this protection against sulfates is significantly increased when using GS reinforcements. The results indicate a higher resistance to corrosion by exposure to 3.5 wt.% magnesium sulfate two times greater for BSC1 and BSC2 specimens reinforced with GS than the specimens embedding CS. In summary, the combination of binary sustainable concrete with galvanized steel improves durability and lifetime in service, in addition to reducing the environmental impact of the civil engineering structures.

Microstructure and mechanical properties of friction welded carbon steel (EN24) and nickel-based superalloy (IN718)

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel (EN24) and nickel-based superalloy (IN718), and the microstructures of three distinct weld zones—the weld interface (WI)/thermo-mechanically affected zone (TMAZ), the heat-affected zone (HAZ), and the base metal—were examined. The joint was observed to be free of defects but featured uneven flash formation. Electron backscatter diffraction (EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and HAZ. Moreover, significant refinement in grain size (2–5 μm) was observed at the WI/TMAZ with reference to the base metal. The possible causes of these are discussed. The microhardness profile across the welded joint shows variation in hardness. The changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening precipitates. The tensile test results reveal that a joint efficiency of 100% can be achieved using this method.

Multifeature Extraction of Three‐Dimensional Topography of Carbon Steel Specimen during Fatigue Process

In order to investigate the variation of three‐dimensional metal surface topography during fatigue process, a three‐dimensional (3D) topography acquisition platform was built with an in situ tensile tester and a three‐dimensional profilometer. Q235 steel specimens were chosen as research objects, and the three‐dimensional surface topography information at various stages of fatigue damage was obtained. Through the characterization of three‐dimensional roughness, combined with surface height distribution and multifractal analysis, the variations of metal surface topography in the fatigue process were described. Results show that the arithmetic mean deviation of the surface (Sa), the width of the multifractal spectrum (Δα), and the mean value of surface height distribution (μ) and its standard deviation (δ) increase nonlinearly with the increase of fatigue cycles. The rate of fatigue damage is slow in the early stage and high in the middle and late stages. The surface height distribution amplitude (A) decreases with the increase of fatigue cycles, which indicates that the height data concentration decreases, and the metal surface becomes uneven. The Bayesian data fusion method was applied to establish a nonlinear mapping between the topography features and the damage, with the above five characteristic parameters (Sa, Δα, A, μ, and δ) as the data layer. Finally, a surface topography feature fusion method is proposed, and a case study is conducted to verify its applicability. The research results can provide reference for fatigue damage assessment.

Improved Dynamic Magnetostriction measurement method based on M-EMAT for the characterization of residual strain

The Dynamic Magnetostriction (DM) measurement method as a nondestructive testing method of ferromagnetic materials, measures the DM curve using electromagnetic acoustic transducer (EMAT) to characterize material and predict the mechanical properties. Lorentz forces and magnetostriction forces contribute mainly to the ultrasonic generation. Only the range of low field, in which the magnetostriction force mechanism is predominant can be used to measure the DM curve, but the boundaries of this range are uncertain. The improved DM measurement method based on shear wave Magnetostriction EMAT (M-EMAT) is proposed and the theory of generation of shear waves is derived. For the M-EMAT, only magnetostriction force mechanism contributed to the generation of shear waves. A theoretical model for the optimization of the transducer is developed, the model is in good agreement with the experimental results. The microstructure changes caused by residual strain will affect the magnetostriction coefficient and the DM curve. Therefore, the DM curves of low carbon steel specimens with different levels of residual strains are measured by the optimized transducer to characterize the residual strain. The normalized results demonstrate that the slope of the DM curve obviously changes with the residual strain. This leads to the conclusion that the DM measurement method can be used to characterize the residual strain of the low carbon steels.

(Invited) Investigating Galvanic Corrosion at a through-Coating Defect on Cu-Coated Carbon Steel Using X-Ray Micro Computed Tomography (μ-CT)

The Nuclear Waste Management Organization (NWMO) is preparing to implement the safe long-term disposal of Canada’s used nuclear fuel in robust, corrosion-resistant used fuel containers (UFC). The current UFC design employs a strong carbon steel vessel, coated with copper for corrosion protection. This project explores corrosion processes that could happen on the surface of a container with a through-coating defect that exposes a small area of the underlying carbon steel, in contact with the copper coating, which corrosion scientists would consider a risk for galvanic (dissimilar metal) corrosion. High resolution ex situ and operando observations of Cu-coated carbon steel specimens with an artificial defect penetrating the copper to the steel, exposed to saline solutions with and without dissolved oxygen, have been made using X-ray micro computed tomography (μ-CT) to reveal the three-dimensional form of the corrosion damage and follow its progression with time (as shown for example in Figure 1). These measurements have shown that the form of the corrosion damage is dependent on both the type of additive manufacturing procedure used to create the Cu coating (electrodeposition or cold spray deposition) and the quality of the Cu/steel interface. In the presence of oxygen, the volume of corrosion damage increases linearly with time, independent of the type of coating, but with a rate dependent on the availability of oxygen. In the absence of oxygen, the corrosion rate is low and decreases with time. Post-experiment characterization of corrosion products by Raman spectroscopy indicated the presence of akageneite (β-FeOOH) and lepidocrocite (γ-FeOOH), depending on the solution conditions within the corroding defect. Figure 1

Mechanical behaviour of double side high performance PSA adhesive applied to painted naval structures

The use of adhesives constitutes a well-established technology in the aeronautical and automotive industries. A rising interest in the use of these materials has appeared in naval industry, where using adhesives in non-structural areas implies the reduction of welding to fix low weight components, making the joining process cheaper and faster. Among the different families of available adhesives, double-sided Pressure Sensitive Adhesives (PSAs) are considered of great industrial interest. A high performance PSA has been employed to join specimens of carbon steel coated with an epoxy painting scheme approved by the naval sector. The present paper reports for the first time the influence of some experimental application variables of this PSA-coated naval steel system on its mechanical behaviour. Standard shear and tensile tests have shown that the curing conditions, surface preparation and paint roughness have considerable effects on the resistance of these adhesive joints.

Directional magnetic Barkhausen noise measurement using the magnetic needle probe method

A directional local magnetic measurement technique as example of measuring the angular dependence of the magnetic Barkhausen noise in electrical and construction steels at typical quasi-static frequency by the magnetic needle probe (MNP) method is presented. The directional measurement configuration of the MNP method is typical of a half-turn search coil sensor coupled to high gain analogue amplification and high order filtration stages, owing to its very weak induced electromotive force. The method exploits the MBNenergy(H) hysteresis cycle (time integration of the square of the MBN voltage signal as a function of the tangent excitation field H) and brings forth stable indicators possibly related to the Magnetocrystalline Anisotropy Energy (MAE). Experimental tests performed on grain-oriented Fe-Si and low carbon steel specimens, and comparison with the conventional search coil measurement results were worth the validation of the MNP method. These results put to the front the good directional selectivity of the MNP method over the conventional MBN sensors adversely affected by the transverse fields at the material surface. Eventually, the printed magnetic needle probe (PMNP) sensor was relatedly described to provide non-invasive directional measurements for continuous structural health monitoring.

An application of FEM in the determination of tensile properties for work-hardened carbon steel by means of small punch test

The determination of tensile properties from a small punch (SP) test by using a finite element method (FEM) has been studied. First, a finite element (FE) simulation of the SP test using true stress-strain curves including post-necking strain data of work-hardened SM490A carbon steel specimens was conducted. The simulation was validated with actual experimental results, which showed that the FE model can effectively reproduce the load-displacement curves without using a damage modeling technique. The FE model was then used to investigate an empirical correlation between the punch loads and the material parameters, including yield strength and ultimate tensile strength. The results indicated that the empirical constants are dependent on specimen thickness and may be valid for only a limited range of test configurations and materials. To expand the applicability of the SP test in the assessment of tensile properties, an inverse finite element method (iFEM) consisting of the iterative finite element calculation, bisection method, and Ludwik’s constitutive model was developed. Through the procedure, true stress-strain curves were constructed from the simulated load-displacement curves of hypothetical materials based on the SM490A steel specimens. Finally, yield strengths and ultimate tensile strengths of the carbon steel specimens were determined and found to be within 5.2% and 2.8% discrepancies, respectively, from the uniaxial tensile test results. iFEM provides consistent estimations of tensile properties with almost no influence of specimen thickness.

Further results on the in situ anaerobic corrosion of carbon steel and copper in compacted bentonite exposed to natural Opalinus Clay porewater containing native microbial populations

AbstractSince 2012, a long‐term in situ corrosion experiment (IC‐A) is being conducted in the Mont Terri Underground Research Laboratory in Switzerland to investigate the corrosion behaviour of candidate canister materials in conditions representative of the Swiss concept for the disposal of high‐level waste and spent nuclear fuel. To date, carbon steel and various types of copper coatings have been retrieved after different exposure periods of up to 3 years, and characterised to establish the composition of the corrosion product, the morphology of the corroded surface, the nature of the interaction between the metal and the surrounding bentonite, and the microbial populations in the bentonite and surrounding porewater. For carbon steel specimens, a complex corrosion product was identified, consisting predominantly of magnetite. Much less alteration on either the metal or the bentonite was observed in the case of copper samples. Low average anaerobic corrosion rates were measured for carbon steel and a very modest amount of alteration was identified on copper. The density and the initial form of the bentonite had a small influence on the rate of corrosion, across all materials. This paper summarises the results of the experimental programme obtained to date and discusses the relationship observed between exposure time and the evolution of the metal–bentonite interface for both carbon steel and copper.

Research on Detection Mechanism of Weld Defects of Carbon Steel Plate Based on Orthogonal Axial Eddy Current Probe.

The uneven surface of the weld seam makes eddy current testing more susceptible to the lift-off effect of the probe. Therefore, the defect of carbon steel plate welds has always been a difficult problem in eddy current testing. This study aimed to design a new type of eddy current orthogonal axial probe and establish the finite element simulation model of the probe. The effect of the probe structure, coil turns, and coil size on the detection sensitivity was simulated. Further, a designed orthogonal axial probe was used to conduct a systematic experiment on the weld of carbon steel specimens, and the 0.2 mm width and 1 mm depth of weld defects of carbon steel plates were effectively detected. The experimental results showed that the new orthogonal axial eddy current probe effectively suppressed the unevenness effect of the weld surface on the lift-off effect during the detection process.

Pengembangan alat uji impak charpy di bagian pengereman, berat pendulum, dan skala ukur pada mesin impak charpydi Laboraturium Teknik Mesin Unhasy

The impact test is a test to determine the strength of the material when receiving a load constantly or suddenly. The previous tool did not meet the test requirements, so it required the development of the pendulum weight sector, the measuring scale and the addition of a braking system. Therefore, this research was carried out for the development of previous tools so that the test tools could meet the requirements and the testing of the tools using ST 41 and ST 60 carbon steel specimens. This research is a research and development study using ADDIE (analysis, design, development, implementation and evaluation) as a reference in conducting research. The development of the tool focuses on the pendulum weight to 10.2 kg, replacing the measuring scale and adding a braking system that uses disc brakes. The results of the expert validation questionnaire got a score of 72.63%, the small respondent data questionnaire got a score of 83% and the large-scale respondents got a score of 85%. This shows that the tool gets a decent score. The results of the performance test of the tool using ST 41 carbon steel with an average impact price of 1.02302732 J / mm and carbon steel ST 60 with an average impact price of 1.2422299 J / mm. This study shows that there is an average difference in the impact price between ST 41 carbon steel and ST 60 carbon steel as indicated by the Sig. (2-tailed) value of 0.484 using independent sample test T-test data processing.

Effect of shot-peening on the passive film formation and corrosion of carbon steel in LiBr aqueous solution

In absorption chillers using LiBr aqueous solution, corrosion problems of carbon steel heat exchangers become more serious as the temperature of the generator increases. To reduce the corrosion problems, various surface treatment methods are applied such as a shot-peening. In this study, corrosion characteristics were investigated for untreated and shot-peened surfaces. Pyrex tube samples containing the specimens and LiBr aqueous solution with Li2MoO4 were made and put into a high temperature oven at 200 °C After 2000 hours, the surface and cross section of carbon steel specimens were observed using field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDS). It was found that the passive films have the characteristic of a double layer consisting of a thick MoO2 layer and thin Fe3O4 layer. Thicker passive films were observed on the shot-peened surface than the untreated one. As a result of corrosion depth measurement, the shot-peened specimens showed a slightly smaller uniform corrosion depth, however, they showed a much smaller pitting corrosion depth than the untreated ones. It is supposed that the shot-peened surface is more effective in preventing the pitting corrosion than uniform corrosion. The results of this study are expected to be applied effectively to the absorption chillers using LiBr aqueous solution to estimate and reduce the corrosion.

Machine learning approach to predict fatigue crack growth

Prediction of fatigue crack growth is an important requirement during estimation of residual life of machine components or during failure analysis. The existing theoretical models are specialized to predict the crack growth for one of the three stage of classical crack growth diagram. In this work, a novel and unified machine learning based approach has been developed to cover both stage-II and stage-III regions of crack growth rate. Three alternative machine learning algorithms are investigated to identify the most suitable algorithm for prediction of fatigue crack growth rate. The models are trained using experimental data conducted on CT specimens of carbon steel subjected to different types of cyclic loading. The comparison of mean squared error and R2 score in terms of accuracy in percentage obtained from the three models is presented. The guidelines for training and tuning of machine learning models are discussed.

Homologous alkyl side-chain diphosphonate inhibitors for the corrosion protection of carbon steels

The interactions of six homologous diphosphonate additives, methylamine-N,N-bis(methylenephosphonate) (MBMP, C1-D), ethylamine-N,N-bis(methylenephosphonate) (EBMP, C2-D), butylamine-N,N-bis(methylenephosphonate) (BBMP, C4-D), hexylamine-N,N-bis(methylenephosphonate) (HBMP, C6-D), octylamine-N,N-bis(methylenephosphonate) (OBMP, C8-D), dodecylamine-N,N-bis(methylenephosphonate) (DBMP, C12-D), with carbon steel surfaces are studied by XPS at pH = 3.0. Structurally, all additives possess two methylenephosphonate moieties connected to a single N atom. The third substituent on N is a non-polar, variable-length alkyl chain, –(CH2)xCH3, where x = 0 (C1-D), 1 (C2-D), 3 (C4-D), 5 (C6-D), 7 (C8-D), and 11 (C12-D). XPS studies (on pristine solid diphosphonate samples and also on carbon steel specimens, immersed in aqueous solutions), indicate significant deprotonation of the diphosphonic acid molecules upon interaction with the metallic surface. They also prove that this surface interaction results in adsorption on the surface via the deprotonated phosphonic acid moieties. The adsorption of inhibitors on the metal surface was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The changes detected in the charge transfer resistance (Rct) and constant phase element (CPE) independently confirm inhibitor adsorption on metal surface. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and Scanning Electron Microscopy was used to investigate the nature of deposited film. Small alkyl chain diphosphonates (C1-D, C2-D and C4-D) exhibited lower corrosion resistance due to the thin, porous and/or incomplete layer formed on carbon steel surface. Longer alkyl chain molecules (C6-D, C8-D and C12-D) were found to adsorb more efficiently and form a more organized and thicker layer. The best results were obtained in the case of C8-D (lower corrosion current, higher Rct and surface coverage). In the presence of C8-D the corrosion rate was reduced by a factor of 6.

Multilayer Coatings Using Epoxy and Superabsorbent Polymer Composite Material with Self Healing Property

The property of superabsorbent polymer (SAP) was investigated as component of composite material for corrosion control application. The composite material is a multilayer coating consisting of SAP particles, epoxy and hardener. The absorption property of SAP at different concentrations of sodium chloride was measured. It included 3% NaCl concentration, which represent the concentration of salt in sea water, an environment which is corrosive to carbon steel. Results showed decreasing absorbency of SAP at increasing concentration of sodium chloride. Predetermined amount of SAP and epoxy were mixed to obtain a homogenous mixture after which the hardener was added and mixed homogenously to form the composite material’s main component. The composite material was studied for absorption properties in an HDPLE substrate and then later applied onto a carbon steel specimen of size 40 mm x 100 cm and thickness of 0.70 mm using paint brush forming a film on the carbon steel surface. After curing, the film was scratched with a definite length using a sharp knife. Immediately, the samples were exposed to cyclic immersion in 3% sodium chloride solution and subsequent drying to run the corrosion test. Results showed that the composite material was able to control corrosion on the surface of the carbon steel which could be attributed to its self-healing property.

Design of reinforced composite material to overcome wear occurrence in transportation pipes

The wear of carbon steel piping systems has been one of the major problems for various industries that involve the high-speed transportation of their raw materials and/or products. Transportation of cement in construction materials manufacturing factories through carbon steel pipes was studied to suggest a resistible material of unsaturated polyester reinforced with glass fiber and the aluminum honeycomb to be used instead of these pipes. A laboratory-scale apparatus was built to examine the wearing in pipes for the carbon steel and composites specimens. The electrical and mechanical prosperities of the composites were studied by using the ASTM standards to find the best conditions for the newly constructed pipes. It was found that, by increasing the concentration of aluminum powder up to 50 wt% of the composite mixture, the electrical conductivity was increased to be within the range of semi-conductance but the mechanical properties decreased. The best concentration of aluminum powder was found to be 30 wt% of the composite mixture, which represents the most suitable electrical and mechanical properties. Also, it was found that the samples of aluminum honeycomb were gained very good electrical conductivity with special mechanical properties that are suitable for many practical applications.

Cathodic protection and DC non-stationary anodic interference

DC stray currents may induce corrosion on buried carbon steel pipelines transporting methane even if in cathodic protection. According to international standard, anodic interference is unacceptable if the IR-free potential is more positive than the protection potential (−0.85 V CSE). But, duration and magnitude of the anodic peak is not defined. This paper describes results of laboratory tests performed in soil-simulating environment on cathodically protected carbon steel specimens suffering DC interference at varying peak current density, anodic potential and duration. Measured corrosion rate is always lower than the theoretical value predicted by Faraday Law. Consequently, it is possible to conclude that cathodic protection has a positive effect towards DC interference. A parameter Time Out of Protection has been defined as the period of time during interference where the potential is more positive than −0.85 V CSE; this factor has been correlated to the measured potential during DC interference.

Measurement of roughness on hardened D-3 steel and wear of coated tool inserts

This research investigation has been carried out in Computer Numerical Control (CNC) turning of 40–50 Hardness Rockwell C (HRC) hardened high chromium high carbon steel (HCHCR-D3) specimen for the findings of surface roughness (Ra) and the tool wear. The HCHCR-D3 steel, which has excellent abrasion and wear resistance, is machined with the physical vapor deposition (PVD) coated carbide (CNMG) turning insert nomenclature based on shape, clearance angle, tolerance and type of tool inserts. The coatings preferred are Titanium Nitrate (TiN), Aluminium Chromium Nitrate (AlCrN) and Latuma for the coating thickness of 3–4μm. The varying input parameters of speed and depth of cut under constant feed rate are used as machining parameters for this CNC turning operation. The machined surface characterization and tool wear have been investigated analytically in this manuscript along with the predicted results of effective stresses and temperatures under dynamic cutting conditions in Deform 3D can be related. The outcomes indicate that the depth of cut and the hardening effect (HRC) are the major influencing parameter on surface roughness. Less tool wear and machining time are obtained by the usage of coated CNMG tool insert for high-speed cutting conditions which results in minimization of wear interruption and growth in surface improvements.

Preparation and evaluation of corrosion resistance of a self-healing alkyd coating based on microcapsules containing Tung oil

A commercial coating was transformed into a self-healing coating by inserting urea-formaldehyde microcapsules (MCs) containing tung oil (TO), to improve coated metal corrosion resistance. The microcapsules were characterized regarding their morphology and chemical composition, and the presence of tung oil as core material was also proven by FTIR analysis. MCs were then incorporated into the matrix of a commercial mono-component alkyd coating, being added in the same proportion as the corrosion inhibitor (zinc phosphate) present in the original commercial coating. Corrosion resistance was evaluated by the comparison between samples coated with an original commercial coating, commercial coating without zinc phosphate and a commercial coating containing MC., employing a corrosive saline medium of NaCl 3.5 % (w/w), where were carried out the electrochemical analysis of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). For this, the stimulus-responsive capacity of microcapsules was proven through mechanical disruption. It was observed that the additive coating presented a satisfactory performance for application in 1020 carbon steel specimens, keeping its properties practically unchanged. The self-healing ability of the coating has been proven and the corrosion protection performance of the coating has been assessed through electrochemical techniques, and the results of the OCP and EIS tests showed that the microcapsules in the coating matrix caused a beneficial increase in barrier properties. Additionally, MC additive coating protected the metallic substrate when it suffers a mechanical defect through the release of the oil and its active protection conditioned to the self-healing effect. Thus, when comparing the types of coatings tested, samples containing MCs of tung oil proved to be a more promising additive than the original additive. Also, a self-responsive stimulus mechanism for this smart coating was proposed based on the blistering caused by the presence of corrosion products.

EFFECT OF ELECTRIC ARC WELDING ON IMPACT OF DIFFERENT MILD STEEL WELD GEOMETRIES

The effect of welding parameters (current, electrode diameter) on the impact of low carbon steel specimens was investigated in this work. Two different geometries namely square butt welded joint and double V welded joint were created. The welding operation was carried out at three different current for welding currents of 90, 110 and 130 amps and electrode diameters of 2.5, 3.2 and 4mm respectively. A Charpy impact testing machine was used to evaluate the impact of the welded samples. It was observed that a low current of 90 Amps for all the welding electrode diameters produced high impact values for both the welding geometries. Also, the 3.2 mm electrode diameter was found to be more suitable for welding the square butt and the double V geometry as it yielded higher impact values. Additionally, the double V geometry showed better performance when compared to the square butt geometry for all the combinations of welding currents and electrode diameters.