Mild Steel Specimens Research Articles

Fracture characteristics and damage prediction in flat steel beams under contact explosions

Research to predict and mitigate local damage of steel elements subjected to contact and close-in explosion remains a topic of interest. In this study, the effects of charge mass, specimen geometry, and explosive charge position on the damage and fracture of flat, mild-steel specimens under contact charges are investigated. From macroscopic and microscopic observations of the fracture surfaces, rupture properties of the flat steel specimen under contact explosion are examined. Based on these observations, the rupture process of flat steel specimens under contact explosion is considered as follows: 1) the opposite surface of a blast -loaded specimen was damaged by spalling due to tensile stress wave, and 2) the rest of the cross-section of a specimen was stretched and ruptured by blast pressure into two pieces. On the microscopic fracture surface observed by a scanning electron microscope demonstrates cleavage, which is caused by brittle spalling and rupture. Their microscopic fracture surfaces are different based on charge positions, specimen thicknesses, and observation points. Furthermore, the effects of charge mass and specimen cross-section on damage to steel specimens under contact explosions are evaluated, and empirical equations to predict thickness limits are developed for spalling and rupture of flat, mild-steel specimens.

Tribo-corrosion behavior of Zn-Ni-Cu and Zn-Ni-Cu-TiB2 coated mild steel

In this investigation , Zn-Ni-Cu and Zn-Ni-Cu-TiB2 were coated on a mild steel specimen using a high velocity oxy fuel thermal spray (HVOF) process. The surface morphology and coated powder distribution of coated specimens were characterized using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray-Elemental mapping. The pin-on-disc (ASTM G99-17) method was used to examine the wear resistance of the coated and uncoated mild steel specimens. Both coated Zn-Ni-Cu and Zn-Ni-Cu-TiB2 on mild steel saw reduced wear volume loss than uncoated mild steel. The coated samples of Zn-Ni-Cu and Zn-Ni-Cu-TiB2 on Mild Steel were put through a scratch test to determine the adhesion strength of the coating with the substrate. The adhesion strength of coated Zn-Ni-Cu and Zn-Ni-Cu TiB2 mild steel was higher than that of untreated mild steel, indicating a solid link between the coating and substrate and minimal delamination. Using the Vickers hardness test to measure the hardness caused by the coating, it was shown that coated samples of Zn-Ni-Cu and Zn-Ni-Cu-TiB2 coated mild steel had significantly higher hardness than uncoated mild steel. Using ASTM G1-03 and ASTM G-31 standards, a 0.2 M HCl immersion cycle test was conducted for 28 days to test the corrosion resistance of coatings in an acidic media (672Hrs). When compared to Zn-Ni-Cu and Zn-Ni-Cu-TiB2 coated mild steel, the weight loss for the uncoated mild steel was significantly larger. Additionally, XRD examination showed that coated samples had less rust on their surface than uncoated samples. Both Zn-Ni-Cu and Zn-Ni-Cu-TiB2 on Mild Steel were anti-corrosive, as evidenced by increased corrosion potential and reduced corrosion current density when compared to uncoated mild steel, according to electrochemical impedance spectroscopy (EIS)/Tafel study in 0.2 MHCl. The outcomes of each test were very encouraging and demonstrated the durability of these coatings against wear and corrosion.

A corrosion and tribo-failure analysis of Ni-P-Cu coated mild steel (AISI-1040) at varied copper concentration

Mild steel considers the key structural ingredient for manufacturing shell and tube heat exchangers. Corrosion and tribo-failures, on the other hand, is a very crucial industrial problem that can even lead to plant shutdown. The present study thus focuses on utilising Electroless Ni-P-Cu coating on mild steel (AISI-1040) for improving its hardness, corrosion and wear resistance properties. The experiments are carried out varying the Cu concentration at 0 g/l, 0.2 g/l, 0.4 g/l, 0.6 g/l, 0.8 g/l, 1 g/l and 1.2 g/l in the electroless solution bath. The microstructure of the coating has been characterised using SEM and XRD analysis. Coating thickness is determined using FESEM, which has been analysed to be uniform. The corrosion failure analysis of the sample has been studied using Potentiodynamic polarization method. The Tafel and Nyquist Plot showcased a comparative corrosion resistance of the prepared samples. The wear resistance, on the other hand is analysed using a pin-on-disc tribometer depicting the tribo-failure study of the experiment. Both corrosion and tribological analysis proved the sample Ni-P-Cu-1 with a copper concentration 1 g/l to be the best-optimised concentration for the experiment. Moreover, Vickers’s microhardness of the coating with respect to mild steel specimen shows an increment of 40–70 %. The study can be readily scaled up by analysing the application on an industrial shell and tube heat exchangers; thus will be helpful for engineers and industrialists of the related field.

Virtual Lab Simulator in Mechanical Engineering Education-Hybrid Approach

Many universities worldwide are partially disrupting their education by the spread of the coronavirus. Consequently, the Universities took the necessary steps to change their teaching methods to online laboratory experiments and workshops. However, universities should continue to maintain their higher education standards and provide a high-quality student experience required for the learning outcomes associated with each degree program. Adhering to online teaching methods for both theory and practical lectures has created a challenge in education. The discussion of the theory lessons by showing PPTs and video presentations was comfortable for students. In addition to that, virtual labs came into existence. These virtual labs had a significant impact on students' learning process, but this did not apply to all labs. This paper projects the outcome of the virtual lab using the explicit dynamic analysis application in solid works software and integration of AR & VR teaching techniques. This paper also includes the work done by the students and the effective outcome utilization of virtual labs compared with practical labs by using mild steel specimens.

Tribological Performance Analysis of Electroless Nickel Coated Mild Steel: A Comparative Experimental Study

In the pursuit of sustainable materials, electroless Nickel coating has emerged as a breakthrough in the development of novel materials with excellent tribological properties. In the present work, NiP and NiB coating has been performed over mild steel specimens for an hour. The tribological character for various loads of NiP and NiB-coated mild steel was determined through tribological tests. The wear behavior of both NiP and NiB-coated mild steel has been analyzed. The NiB-coated mild steel was found to show less coefficient of friction and wear rate than NiP-coated mild steel.

Development of polyaniline – TiO2 nano composite films and its application in corrosion inhibition of oil pipelines

Oil and gas industries are the driving force of Oman’s economy and have a relatively diversified wealth among Gulf Cooperation Council Countries. Oil pipelines play an important role in transporting oil and gas from the wellheads to the processing facilities. Corrosion normally results in the deterioration of the pipe material with exposure to the surrounding environment and complete control of corrosion is difficult. Corrosion in oil transmission pipeline would be effectively addressed by introducing conventional corrosion control practices. Most of the conventional techniques are either less effective or too expensive in controlling the deterioration rate of the pipe materials. However, preventative measures may be taken to protect the metal surface from corrosion is a possible way to reduce corrosion. This research work aimed to develop a novel technique utilizing Polyaniline (PANI) and Titanium dioxide (TiO2) nanocomposites to assess its corrosion inhibition effect on mild steel. TiO2 was synthesized by sol-gel process. Polyaniline-Titanium dioxide (PANI/TiO2) nanocomposites were coated on mild steel specimen by dip coating technique. The coated specimen was subjected to stability studies at different environmental conditions and exposure time. The stable thin film coated specimen was employed in the corrosion inhibition studies at various processing environments. The characteristics of TiO2 nanoparticles and PANI-TiO2 thin films were analyzed using Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive X-Ray analysis (EDX) and X-Ray Diffraction (XRD) and Dynamic Light scattering (DLS). Scanning Electron Microscopy (SEM) was used to visualize the surface morphology and micro structural characteristics of the preformed thin layer. Potentio dynamic test, Atmosphere test and Wet/Dry tests were carried out to investigate the corrosion behaviour of coated and uncoated specimen. The study demonstrates that the Polyaniline – TiO2 composite thin films fabricated using dip coating technique with minimum film thickness could be a feasible solution in controlling the corrosion in oil pipelines with good film stability, high durability, with a cost effective and environmentally friendly approach.

Synthesis and characterization of new quinolinyl phenol based polybenzoxazine: thermal stability, hydrophobicity and corrosion resistant properties

A new class of quinolinyl phenol-based benzoxazines (QP-a, QP-cha, QP-2eha) were synthesized by using quinolinyl phenol [4-(6-chloro-4-phenylquinoline-2-yl)phenol] with three structurally distinct amines, namely aniline (a), cyclohexylamine (cha), and 2-ethylhexylamine (2eha) through Mannich condensation reaction using an appropriate solvent and reaction conditions. By using FTIR and 1H-NMR spectroscopy methods, the molecular structures of the benzoxazines QP-a, QP-cha, and QP-2eha were identified. From the differential scanning calorimetry (DSC) analysis, the exothermic peak maximum of benzoxazine monomers viz., QP-a, QP-cha, QP-2eha were observed at 218, 202 and 187 °C respectively. The thermogram obtained from TGA studies the amount of char yield obtained for poly(QP-a), poly(QP-cha) and poly(QP-2eha) were found to be 45, 24, and 32%, respectively. The value of limiting oxygen index (LOI) for polybenzoxazines was calculated using the value of percentage char yield obtained from TGA studies infer that these benzoxazines exhibit good flame-retardant characteristics. Data from water contact angle studies ascertain that these samples possess good hydrophobic properties in the range of 129–138°. Results from corrosion studies infer that the mild steel specimens coated with these benzoxazines were found to be more stable and offer better surface protection against corrosion under the conditions studied.

Isatin Schiff base is an effective corrosion inhibitor for mild steel in hydrochloric acid solution: gravimetrical, electrochemical, and computational investigation

This paper describes the synthesis and characterisation of an isatin Schiff base, namely 2-(2-oxoindolin-3-ylidene) hydrazinecarbothioamide (OHB). The chemical structure of OHB was elucidated through proton-nuclear magnetic resonance (1H-NMR), carbon-nuclear magnetic resonance (13C NMR), and Fourier-transform infrared (FT-IR) spectroscopic techniques. OHB was evaluated for its corrosion inhibition ability on mild steel specimens in 1 M HCl using gravimetrical methods and electrochemical measurements such as electrochemical impedance spectroscopy (EIS) and potentiodynamic techniques complemented with microscopic analysis. The results indicated that OHB is a mixed-type inhibitor and showed good corrosion inhibition, with a maximum corrosion inhibition efficiency of 96.7% at a concentration of 0.5 mM and 303 K. The inhibition performance increased with an increasing OHB concentration and decreased with increasing temperature. The inhibition efficiency was attributed to the formation of a protective film on the surface of the tested mild steel coupon. The electrochemical impedance studies also indicated that the charge transfer resistance increased with an increase in OHB concentration. The morphological analysis confirmed the inhibition performance of OHB and the protective barrier film conformed to Langmuir monolayer adsorption. The experimental and theoretical corrosion kinetics and thermodynamic parameters were in agreement and revealed that an adsorption film of Fe–N coordination bonds formed on the mild steel surface.

Antifouling paint formulations with ZnO and Fe2O3 nano-paints for marine applications

The specific objective of the work is to develop antifouling paint formulations for coating marine vessels and structures using nanoparticles as functional additives. The Preparation of nano paints was undertaken by embedding the ZnO and Fe2O3 nanoparticles in linseed alkyd resin and mixing them with soya lecithin, mineral turpentine oil, and also thickener was also added. By using these various nano paints formulations, fouling properties was reduced with increased anti-bacterial properties based on which the coatings were examined for their corrosion properties. The development of antifouling paints with nanoparticles as biocides is expected to significantly improve the efficacy of antifouling paints.The results obtained suggest that with an increase in the concentration of nanoparticles, there was an improvement in the antifouling and anti-corrosion. It was also observed that the mild steel specimens were coated with antifouling paint formulations when immersed in the seawater for 120 days for testing and the properties were observed by utilizing Scanning electron microscopy, SEM - EDX, X-ray beam Diffraction, and Fourier transform infrared spectroscopy. It found an improvement in anti-fouling showed by Fe2O3 coated specimens and an improvement utilizing ZnO when contrasted with bare paint.

TAGUCHI METHOD APPLIED FOR THE INVESTIGATION OF CORROSION LEVEL ON METAL INERT GAS WELDING OF MILD STEEL

Mild steel has a wide range of uses such as in the construction field, automotive field, machinery industry, cookware, and pipeline. Metal Inert Gas (MIG) welding act as an assembly method of mild steel. Corrosion level is a common problem that occurs in MIG welding on mild steel. In this study, the suitable welding parameters such as voltage, number of passes, and method of welding were chosen in the experimental testing and the experimental testing was planned by using the Design of Experiment (DoE) as part of Taguchi method. The welded mild steel specimens were evaluated using a corrosion test. The data analysis was done by using Taguchi method. For the parameter to be the optimum welding parameter, the corrosion level was as low as possible. In this case, the S/N ratio smaller is better common interest is chosen. By using the Minitab 18 software, the S/N ratio was calculated. Hence from the result, the optimum parameter is 9V voltage, three passes and the welding method was circle push.

Al2O3 and CuO nano particulate-based paints for marine applications

The present study focuses on the Preparation of Aluminum Oxide, and Copper oxide antifouling coatings to prevent or reduce corrosion and fouling in ships and marine vehicles. Al2O3 and CuO nanoparticles were prepared using the ball milling process. The nano paints were prepared using these nanoparticles as pigment and linseed alkyd resin as a binder. Mild-steel specimens coated with nano paint were immersed in seawater for 120 days and the properties were studied using Scanning electron microscopy, SEM—EDAX, X-ray Diffraction, and Fourier transform-infra red spectroscopy. It found an improvement in anti-fouling exhibited by Al2O3 mild steel plates and also an improvement using CuO when compared to bare paint. Contact angle measurement showed a marked increase for base paint which indicates its hydrophobic nature.

Cardanol and bisphenol-F based benzoxazines with zirconium phosphate reinforced composites coating for protecting the mild steel surface from corrosion

The present work is to develop and characterize the benzoxazines from cardanol and bisphenol-F with imdazole core based amine in order to utilize them in the form of (50/50 wt%) blended composites coating for corrosion resistance application. The benzoxazine blends were reinforced with varying weight percentages of (0.5, 1, 1.5, 2.0 and 2.5 wt%) of 3-glycidoxypropyltrimethoxysilane (GPTMS) functionalized zirconium phosphate (ZrP) to obtain respective composites blended coatings. The thermal stability of composites was studied by thermogravimetric analysis (TGA). In order to ascertain their hydrophobic behavior the water contact angle studies were carried out and the values obtained for 0.5, 1, 1.5, 2.0 and 2.5 wt% GPTMS functionalized ZrP reinforced (50/50 wt% of C-ima/BF-ima) benzoxazines blended composites are 114,116,117,119,120 and 123° respectively. The UV shielding behavior of ZrP reinforced polybenzoxazine blended composites material was also studied by UV-Vis spectroscopic technique and the results obtained infer that these materials possess good UV shielding behavior. ZrP reinforced benzoxazine blended composites were coated on the mild steel specimens and their corrosion resisting behavior was studied. Results of Nyquist plot and Tafel plot, ascertain that among the coated specimens, the specimen coated with 2.5 wt% ZrP reinforced poly(C-ima/BF-ima) blended composites exhibits highest corrosion resisting efficiency.

Anticorrosion Performance of Magnesium Hydroxide Coatings on Steel Substrates

Sewerage systems consist of several different parts, components and materials. Many of them are metallic structures, such as pumps, valves, ladders and wells, which are necessary for the proper operation of wastewater transport systems. Wastewater pipelines can be a highly corrosive environment, mainly due to the presence of biogenic sulfuric acid. In the present study, seven magnesium hydroxide and one magnesium oxide materials were used as protective coatings applied onto the surface of certain stainless steel and mild steel specimens against sulfuric acid corrosion. The coated specimens were subjected to accelerated sulfuric acid spraying tests and their behavior was evaluated by using optical observation, mass measurements and electrochemical impedance spectroscopy. According to the results, the coating prepared from a magnesium hydroxide powder with relatively low specific surface area and smaller particle size was optimal for the protection of the examined steel specimens.

Use of Trochodendron Aralioides Extract as Green Corrosion Inhibitor for Mild Steel in 1M HCl Solutions

Recently, there is an interesting discussion that has transpired around the world about the usage of plant extracts as corrosion inhibitors. We report that to control corrosion in mild steel (MS) specimens in a 1M HCl medium, Trochodendron aralioides (T. aralioides) extract was used as an economical green corrosion inhibitor. The various tests, namely, potentiodynamic polarization, weight loss measurements and electrochemical impedance spectroscopy (EIS) were performed to analyze the inhibition efficiency (IE) of the extract. The highest IE value of 96.42% was seen at 250 ppm, with the IE% increasing as the extract concentration increased. Potentiodynamic polarization suggests that T. aralioides plant extract acts as a mixed-type inhibitor. UV–visible (UV–Vis) and FT-IR spectroscopy were performed with the inhibitor to study the adsorption mechanism and surface analysis of the specimen, respectively. The results revealed that plant extracts form a protective film on the surface of the specimens, increasing inhibition and thereby reducing corrosion. Surface morphological studies such as AFM, EDX and SEM tests were performed in the presence and absence of the inhibitor with the results being analyzed by observing the surface of the metal.

Tribological Characteristics of Stellite Hard faced Layer on Mild Steel

Hardfacing is the oldest method of surface engineering for obtaining diverse characteristics and extending the life of materials. Even with typical use, all metal parts will corrode over time. As a result, they may lose their functioning, necessitating the purchase of a new part. This may occur more commonly in particular industrial applications, such as mining or agriculture. Hardfacing is a great solution for any metal element that is likely to wear over time. Hardfacing is typically done to worn rebuilt gear, but it can also be applied to new equipment to make it more wear-resistant. Hardfacing parts from older equipment can save you anywhere from 25 to 75 percent on replacement costs. Hardfacing can help extend the life of parts on latest equipment by up to 300 percent. Here chosen hardfacing technique as Tungsten Inert Gas Welding (TIGW) process to deposit stellite electrodes on base metal (i.e mild steel). The works is focus about deposit the hardfacing layers on mild steel specimens and perform comparative study of stellite -1 and stellite-12 hardfaced layers applied on mild steel specimens. The Objective of the project is to obtain better wear characteristics, hardness and better micro- structural properties of material.

CORROSIVE INFLUENCE OF VARIED SALT SOLUTIONS CONCENTRATION ON MILD STEEL

This study is focused on the corrosive effects of varied salt solutions concentration on two mild steel specimens (API 5L X42 and API 5L X60). Gravimetric method was adopted in the evaluation of the weight loss and corrosion rate of the specimens. The hardness of the test specimens after dipping in corrosive solutions was examined. Potentiodynamic polarisation technique was also used to compare the most corrosive medium. API 5L X42 and API 5L X60 specimens exhibited highest corrosion rates of 9.593 mmpy and 9.698 mmpy respectively in solution A that contained 2.0 M NaCl, 3.0 M CaCl2 and 0.5 M Na2CO3. They also exhibited the lowest corrosion rates of 7.642 mmpy and 7.836 mmpy respectively, in solution H that contained 0.5 M NaCl, 3.0 M CaCl2 and 2.5 M Na2CO3. The API 5L X42 mild steel specimen in solution H exhibited the highest hardness value of 369 HV after immersion in the corrosive medium. The hardness of the corroded specimens decreased when compared to their hardness before immersion in the corrosive media, which indicates that the varied salt solutions impaired the surface morphology of the specimens’ thereby promoting indentation.

2D MoS2-hBN hybrid coatings for enhanced corrosion resistance of solid lubricant coatings

Molybdenum disulphide (MoS2) is commonly utilized as a solid lubricant due to its outstanding wear resistance properties. However, the application of MoS2 is restricted due to its high tendency of oxidation and corrosion when exposed to oxygen and humid air. Here, in this work, we developed a 2D hybrid structure by incorporating the 2D material, hexagonal boron nitride (hBN), with MoS2 to enhance the corrosion resistance properties. MoS2-hBN 2D hybrid coatings with varying concentrations of hBN nanosheets were deposited onto mild steel specimens to evaluate tribological and corrosion properties. The friction studies were carried out using a high-frequency reciprocating tribometer (HFRR) and found that hybrid coatings showed a slightly higher coefficient of friction (CoF) than pure MoS2 coating due to hBN addition. Electrochemical corrosion studies of the coatings were conducted in 3.5 wt% NaCl solution. Potentiodynamic polarization and electrochemical impedance spectroscopy studies depicted lower corrosion rate and higher corrosion resistance for MoS2-hBN coatings than pure MoS2 coating. The increase in hBN content resulted in an enhanced corrosion resistance. Raman spectroscopy studies of corroded coatings revealed the presence of a high concentration of MoO3 in pure MoS2 coating, while oxide peaks were nearly absent in MoS2-hBN coatings. XPS analysis depicted comparatively lower oxidation and MoO3 concentration in hybrid coating compared to pure MoS2 coating.

Defect resonance frequency of spherical pore within isotropic elastic solid

Ultrasound based porosity imaging in metals, composite or additive manufactured structures pose a challenge due to various absorbing media. This paper addresses this problem by developing a defect resonance frequency equation that will be used for individual porosity imaging. An analytical model is developed for closed spherical shell supported on elastic foundation based on the six mode shell theory. The defect resonance frequency is calculated from the breathing mode, corresponding to maximum out-of-plane displacement, when supporting stiffness tending towards rigid condition. Thereafter, steady state and explicit dynamic analysis are carried out for a mild steel specimen with single and multiple pores to detect the defect resonance frequency along with defect mode. Further, the defect resonance frequency is validated with experiment involving a mild steel specimen with single spherical pore. The numerical and experimental results are good agreement with the results obtained from defect resonance frequency equation. This defect resonance frequency equation can be used for high resolution imaging of porosities.

Thermo-reversible self-healing polymeric coatings derived from gum rosin

The growing demand for the development of bio-based, greener and more sustainable polymeric systems was the inspiration to develop two bio-based thermo-reversible polymers derived from gum rosin, a product of pine trees, being reported in this article. The Diene moieties were inserted into the backbones of rosin-based polymers, and thermo-reversible Diels-Alder (DA) bonds were formed between the diene moieties of the polymers and the bismaleimide crosslinkers. The introduction of thermo-reversible linkages to the polymer improves the durability of the material by extending its life span and improving its mechanical properties as well. After damage, the material shows self-healing due to the thermo-reversibility, which causes the DA bonds to de-crosslink, allowing the material to reflow to the wounded site and seal the fracture. The DA and Retro-Diels-Alder (r-DA) reactions are analyzed by differential scanning calorimetry. The scanning electron microscope (SEM) was used to evaluate the self-healing capabilities of polymeric materials that were applied on glass surface, mild steel, and concrete specimens. Artificial scratches were created, and the repairing process was examined.

Corrosion protection properties of poly((benzoyl phenyl) methacrylate-co-methoxy ethylmethacrylate) coating on mild steel

The copolymer, poly(BPM-CO-MOEMA) has been synthesized from different monomer feed ratios of benzoylphenyl methacrylate (BPM) and methoxyethyl methacrylate (MOEMA) was achieved using the free radical solution polymerization technique. The thermal stability of the synthesized copolymers was studied by using TGA and DSC. The molecular weight of the copolymer was determined by GPC. The corrosion protection efficiency of the mild steel specimens coated with different mole ratios of the copolymer has been investigated using electrochemical techniques like EIS and potentiodynamic polarization studies in 1 M H2SO4. The observation of electrochemical results confirmed that the copolymer coating shows good protection efficiency for mild steel in the corrosive media. The surface and morphological investigations also confirm the barrier effect of the copolymer film on the metal surface against the invasion of corrosive ions.