St3 Steel Research Articles

Investigation of the Effect of T-Consciousness Fields on the Mechanical Properties of Materials

In another study titled “Investigation of the Effect of T-Consciousness Fields on the Mechanical Properties of Materials,” (Authors: Mohammad Ali Taheri, Firouz Payervand, Reza Yazdanparast, Farzad Ahmadkhanlou, Sara Torabi, Farid Semsarha*), by use of tensile testing, the effects of two types of TCFs on the mechanical properties of two types of steel were investigated. The obtained results demonstrated that the strength and brittleness of ST-37 steel increased in dynamic loading conditions under the treatment of TCF 2. Moreover, softening of the ST-37 carbon steel and AISI 4340 alloy steel in quasi-static loading conditions under the treatment of TCF 1 and 2 were observed, respectively. In this experiment, the effects of different types of TCFs on the material were confirmed.

Sliding Friction of R6AM5 Steel on St3 Steel in Lubricating M14G2TS Oil Containing a Hydrous Magnesium Silicate Powder

Sliding Friction of R6AM5 Steel on St3 Steel in Lubricating M14G2TS Oil Containing a Hydrous Magnesium Silicate Powder

Full and partial compression fatigue tests on welded specimens of steel St 52-3. Effects of the stress ratio on the probabilistic fatigue life estimation

The fatigue strength of structures subjected to cyclic loading depends strongly on the stress ratio. Particularly, in case of welded steel structures this fact is not considered in the corresponding standards nor in the guidelines. Experimentally, two approaches are used to study the effect of stress ratio on the fatigue life. On the one hand, based on the S-Ncurves obtained from tests performed at different stress ratios, the fatigue life under a particular stress range is estimated. On the other hand, the stress amplitude corresponding to a constant fatigue life is estimated by applying the failure criteria for fluctuating stress like the Goodman–Haigh relationship. This paper presents a general probabilistic model, which estimates the S-Nand Goodman–Haigh curves for any stress ratio. Afterwards, this model is applied on data obtained from full and partial cyclic compression loading tests performed on welded specimens made of steel St 52-3. The tested details correspond to the permissible notch condition limit occurred in highly stressed structures used to build ships.

Corrosion inhibition of steel by selected homologues of the class 3-alkyl-5-amino-1H-1,2,4-triazoles in acidic media

The use of hydrochloric acid in the treatment of the bottomhole formation zone leads to the significant corrosion of metals, as well as hydrogen and chloride stress cracking of pump compressor pipes. In order to solve this problem, corrosion inhibitors are added to a hydrochloric acid solution. This article presents the results of a study of the anticorrosive activity of a number of derivatives of the class of 3-alkyl-5-amino-1H-1,2,4-triazole under the conditions of hydrochloric acid corrosion of low-carbon steel. During the study, selected 3-alkyl-5-amino-1H-1,2,4-triazoles were synthesized. Their structure was confirmed and proved using NMR spectroscopy and HPLC/MS spectrometry. Regularities of the anticorrosive ction of the investigated compounds have been established using polarization electrochemical studies and gravimetric direct corrosion tests. Corrosion rates, inhibition coefficients and degrees of protection have been calculated for all inhibitors. The probable mechanism of the inhibitory action of the studied compounds has been substantiated using quantum chemical calculations based on the density functional theory using the Gaussian program. It was shown that the structure of the alkyl substituents has the greatest effect on the inhibitory activity of the studied compounds. The mechanism was proposed for the adsorption of the inhibitor, which explained the increase in protective properties with an increase in the length of the alkyl substituent. The high hydrophobicity of the aliphatic fragment, not involved in the chemisorption process, additionally prevents the acid solution from contacting the metal surface, while the heterocyclic moiety ensures the sorption of the inhibitor on the metal surface. As a result, it was shown that derivatives of the homologous series of 3-alkyl-5-aminotriazole are suitable as inhibitors of acid corrosion of ST-3 steel. The minimum length of a hydrocarbon radical at which significant inhibitory activity was observed is 7 carbon atoms. Protection degrees of 65–85% were achieved when 3-heptyl-5-amino-1H-1,2,4-triazole additives at a concentration of at least 2 g/L were added to the hydrochloric acid solution.

Penggunaan Katalis Kalsium Karbonat Pada Karburasi Padat Baja ST 37

In modern era, we find many equipment that uses metal as the main ingredient in its manufacture. The use of metals that have good hardness is very necessary, especially in the engine parts which must always be in contact with other engine parts. One way to increase metal hardness is to add carbon to the metal. The process of adding carbon is by solid carburizing. The use of calcium carbonate catalyst can also be used to accelerate the reaction of the solid carburizing. This study aims to determine the effect of the carburizing process on ST 37 steel either by using a catalyst or without a catalyst to the hardness test. From the results of observations and data collection that has been done, the average hardness value of raw material is 47.9 HRB. For ST 37 steels which are heat treated at 900ºC, normalizing process and quenching process have an average hardness value of 47.5 HRB and 49.05 HRB. As well as ST 37 steel which is carried out by a solid carburizing process using catalysts and without catalyst, each has a hardness rate of 48.6 HRB and 48.2 HRB. From the results above it is known that the cooling time affects the hardness of steel ST 37. The carburizing process can increase the hardness due to the addition of carbon to the steel. Catalysts play a role in increasing the hardness of steel, this is because the catalyst can accelerate the rate of reaction in carburizing

PENGARUH VARIASI ARUS PENGELASAN SHIELDED METAL ARC WELDING TERHADAP KEKUATAN TARIK BAJA ST-37

In metal manufacturing, welding and casting became an important focus in its development. Going to industrial era 5.0, efficiency in welding and casting is very important. Welding is one of the simplest methods of joining metals to form the desired machining structure. Shielded Metal Arc Welding has several variables that can affect the welding results. Current strength has an important influence on the quality of the weld. So research on the effect of current strength on the results of welded joints on its mechanical strength is needed. In this study, the mechanical strength tested is the tensile strength and the current susceptibility used is the commonly used 80 to 140 Ampere using ST-37 Steel. The highest maximum loading value occurs in the sample with a current of 80A. However, the highest fracture and yield loads occurred in the sample with a current of 140A. All types of the highest tension occur in the sample with a current using a current of 140A which has the potential to be able to withstand high tensile strength.

Interrelation of the Composition of Steel Treated by Electrospark Alloying and the Properties of Obtained Composite Surface

Basing on the study of the elemental composition of surface composites obtained on 45, 65G, and St3 steels by electrospark alloying using processing electrode from T15K6, VK8 hard alloys, as well as 45 and St3 steels (the “steel on steel” option), it was shown that the resulting surface layers are ~70% composed of the material steel substrate modified by electro-discharge treatment. The influence of the steel composition on the coefficients of the processing electrode material transfer on the substrate, on the roughness, microhardness, and wear resistance of the resulting surfaces has been studied. It is shown that the wear resistance of the resulting composites is determined mainly by the nature of the treated surface and, to a much lesser extent, by the processing electrode material, roughness, and microhardness of the surface.

Novel glycoluril pharmaceutically active compound as a green corrosion inhibitor for the oil and gas industry

• GCU is introduced as a green corrosion inhibitor. • Maximum inhibition efficiency of GCU is 95.62% at 100 mg/L/0.08 mM. • GCU is a mixed-type corrosion inhibitor. • Bond length of Fe-O is approximately 2.4 Å. • Adsorption energy of GCU on Fe(1 0 1) surface is − 390.1 kcal/mol. The corrosion of St3 steel in 1 M NaCl saturated with CO 2 and H 2 S is a large problem in the chemical industry; therefore, creating green and more efficient inhibitors is an urgent task. However, there have been extremely limited research results related to this problem. In this research, a novel glycoluril pharmaceutically active compound (GCU) was first introduced as a green corrosion inhibitor for St3 steel in 1 M NaCl saturated with CO 2 and H 2 S. The inhibition properties of the novel glycoluril pharmaceutically active compound were fully characterized by thermodynamic, gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), linear polarization resistance (LPR), density functional theory (DFT), molecular dynamics (MD) simulation, scanning electron microscopy (SEM) and energy dispersive X–ray spectrometry (EDX) methods. The obtained results indicated that this inhibitor is an excellent inhibitory molecule, and its maximum protection degree was 95.62% at 100 mg/L/0.08 mM. The adsorption behaviour of this inhibitor was characterized from a Langmuir isotherm. Electrochemical studies demonstrated that this molecule is a mixed–type corrosion inhibitor. The theoretical calculations indicated a good correlation with the experimental results and confirmed that the adsorption–inhibition character depends on the molecular structure of the inhibitor and that the protonated form of the inhibitor is more inhibited than its neutral form.

Modeling and Optimizing the Penetration in the Submerged Arc Welding Process in the Presence of ZrO2 Nanoparticles

Abstract Penetration is one of the most vital parameters because of its influences on weld strength and weld quality. Choosing the input parameters in submerged arc welding (SAW) has significant effects on input heat into the weld pool, which affects the quality of weldment. The amazing advancement of nanotechnology in various industrial areas persuaded researchers to use nanoparticles in new research. Zirconium dioxide (ZrO2) nanoparticles were selected in order to identify their effects in the weld pool in combination with other welding input parameters. The five-level, five-parameter central composite rotatable design, response surface methodology, the slime mold algorithm, and Harris hawks optimization were utilized to design and develop the research and finally to predict and optimize the weld penetration affected by the arc voltage, welding current, nozzle-to-plate distance, welding speed, and the thickness of ZrO2 nanoparticles coated on ST-37 steel. The main and interaction effects of input parameters on weld penetration were drawn. The results demonstrated that weld penetration decreased initially by increasing the thickness of ZrO2 nanoparticles up to 0.25 mm, which was due to reversing Marangoni convection mode. Furthermore, weld penetration increased with increase in ZrO2 nanoparticles above thicknesses of 0.75 mm. The reason for increase in weld penetration was because of the fact the ZrO2 nanoparticles have low thermal conductivity, which leads to less heat transfer. The results confirmed that the accuracy of model obtained by slime mold algorithm was 5.2 % more than response surface methodology.

Formation of the composite polymercontaining coatings on St3 steel using cold gas-dynamic spraying technology

Formation of the composite polymercontaining coatings on St3 steel using cold gas-dynamic spraying technology

Can the corrosion-penetration depth into a metal be estimated from an image of the corroded surface?

This paper presents experimental studies of the penetration of corrosion into the metallic surface of laboratory samples of St3 steel. The results of laboratory studies of the possibility of estimating the corrosion-penetration depth into the metal are presented, using the proportions of the color components in a digital image of the corroded surface, and it is established how the variation of the corrosion-penetration depth into the metal depends on the median contrasts in a digital image of a corroded surface. The factors that affect the radiance variation of the RGB components in an image of a corroded surface are theoretically analyzed.

Дослідження механічних властивостей і зносостійкості плазмових покриттів на основі інтерметаліду Fe-Al

Studies of the mechanical characteristics and abrasive resistance of FeAl-based plasma sprayed coatings are presented. Coatings were obtained by plasma spraying method using iron aluminide powders of Fe3Al, Fe-AlMg and Fe-TiAl systems. The powders were prepared by mechanochemical synthesis. The mechanical characteristics (hardness and elastic modulus) of the coatings were determined by microindentation method. It has been found that the hardness of the coatings is in the range of 2.9…5.4 GPa, the elastic modulus is in the range of 80…100 GPa. It is shown that the gas-abrasive resistance of all tested coatings at room temperature exceeds the wear resistance of St3 steel 1.4…4.3 times; when dry abrasive/rubber wheel testing the resistance of the coatings exceeds the resistance of St3 2.1…3.8 times. The resistance of Fe3Al, Fe-AlMg and Fe-TiAl coatings is higher 2.2…3.1 times than resistance of St3 steel under conditions of gas-abrasive wear at a temperature of 550 °C; the resistance of Fe3Al and Fe-TiAl coatings under the same conditions exceeds the resistance of heat-resistant steels 1.2…1.5 times. In all cases Fe3Al coating has the highest wear resistance because of low porosity and low content of brittle phases in the coating. An assessment of the relationship between the mechanical properties of coatings and wear resistance showed that the wear resistance of coatings increases with an increasing of their elastic modulus. Based on the results of studies the possibility of using FeAl-based coatings for the protection and hardening of parts and constructions operating under conditions of abrasive wear at temperatures range from 20 to 550 °C is shown.

Deformation defects of the structural material as a factor of life aging

The paper presents the statistical characteristics of deformation defects on the surface of steel St 20 laboratory specimens obtained under alternating loading. Digital images of the deformed surface layer are used to analyze dynamics of deformation defects accumulation. The structure of deformation defects is represented by a change in characteristics of their distribution on a surface. Discrete deformations of a sample surface layer characterize dynamics of microplastic deformation accumulation during diffuse fracture. The authors suggested a methodological approach to determine the state of damage to a structural material in the range of elastic deformations by deformation defects parameters of a laboratory specimen surface.

Açılı Derin Çekme Kalıplarında Dikdörtgen Şekilli Kapların Derin Çekilebilirliğinin Araştırılması

Deep drawing is the process of obtaining three-dimensional containers of certain depths and shapes under pressing forces with the help of drawing molds of sheet materials. In this study, the numerical shaping of rectangular cups in angled deep drawing dies was investigated experimentally and by using the finite element method (FEM). For this purpose, die/blank holder surfaces have α=0°, α=3°, α=6°, α=9°, α=12° and α=15° angles in order to facilitate material flow into the die cavity. The punch and die corner radii are taken as 8 mm. St37 steel sheet with a thickness of 0,9 mm was used as the test material. The experiments were carried out by applying die/blank holder forces of 2500 N, 5000 N, 7500 N and 10000 N. The effects of angles and die/blank holder force on limit draw ratio, wall thickness and the damage of cups were investigated experimentally and numerically, and optimum punch force was determined. Obtained experimental results were compared with ANSYS results. As a result, it has been determined that the increase in die/blank holder surface angles in drawing dies with rectangular geometry with different angles provides a higher limit drawing rate than conventional dies. It has been seen that the experimental results and numerical results are approximate values.

Experimental Work for Bar Straightness Effect Evaluation of Split Hopkinson Pressure Bar

Bar straightness is one of several factors that can affect the quality of the strain wave signal in a Split Hopkinson Pressure Bar (SHPB). Recently, it was found that the bar components of the SHPB at the Lightweight Structures Laboratory displayed a deviation in straightness because of manufacturing limitations. An evaluation was needed to determine whether the strain wave signals produced from this SHPB are acceptable or not. A numerical model was developed to investigate this effect. In this paper, experimental work was performed to evaluate the quality of the signal in the SHPB and to validate the numerical model. Good agreement between the experimental results and the numerical results was obtained for the strain rates and stress-strain relationship for mild steel ST37 and aluminum 6061 specimen materials. The recommended bar straightness tolerance is proposed as 0.36 mm per 100 mm.

Coercive force of double layer ferromagnetic materials

Peculiarities of the coercive force (CF) measuring of inhomogeneous ferromagnetic materials, in particular layered ones, are considered. The concept of effective CF of layered ferromagnetic materials is introduced. The analysis of the magnetic fluxes distribution in a double layer ferro-magnetic material during its reversal magnetization by an attachable transducer with a U-shaped core made of soft magnetic material is carried out. An analytical expression of the effective CF for such class of materials for the case of the same layers’ thickness and linear approximation of their demagnetization curves is obtained. It was found that the effective CF of a double layer ferromagnetic material is determined not only by the CF of its individual layers, but also by the values of their residual induction. Experimental verification of the obtained results was performed on experimental samples, which were collected from steel 08kp (sample # 1) and steel St3 (sample # 2) plates. Each of the samples was a stack of 6 plates each measuring 87×50×1 mm. With tight compression of the plates and complete elimination of the gaps between them, these samples can be considered as single layer ferromagnetic structures with a thickness of 6 mm. To model a double layer ferromagnetic material with the same layer thickness, sample № 3 was used. Its the upper part consisted of the three steel 08kp plates and the lower part – of the three steel St3 plates. To measure the magnetic parameters of these samples the KRM-Ts-MA type magnetic analyzer was used. The device permit to measure the CF, residual induction and other parameters of the hysteresis loops of ferromagnetic materials in the closed magnetic circuit by attachable type transducers with U-shaped core. The transducer used with the magnetic analyzer during the experiments had poles with an area of 16×32 mm and the distance between the edges of the poles: inner – 32 mm, outer – 64 mm. It is shown that the discrepancy between the calculated value of the effective CF of the double layer ferromagnetic material (sample # 3) from steel 08kp and St3 according to the obtained expression and the measurement results is about 3%. This confirms the adequacy of the proposed model of reversal magnetization of double layer ferromagnetic material and the correctness of analytical calculations.

Increasing the wear and corrosion resistance of steel parts by methods of complex boronikeling and borovolframing

The paper presents ways to increase the wear and corrosion resistance of steel parts by chemical and thermal treatment methods. Comprehensive studies of the structure and properties of St3 steel samples were carried out after simultaneous complex saturation with boron and nickel, boron and tungsten from saturating coatings based on boron carbide. Both compounds of these elements (oxides, carbides, borides) and pure metals were used as suppliers of nickel and tungsten. Studies have shown that multicomponent saturation processes make it possible to form a multiphase structure of a surface layer with a complex of useful properties. Moreover, by chemical-thermal treatment it is possible to obtain such a combination of properties of the hardened product, which cannot be obtained by other methods.

Оценка влияния дисперсности структуры стали на магнитные и механические свойства

Introduction: The control of the mechanical properties of structural steels is one of the main processes that regulate the service life of equipment. In most technical processes (pressure treatment, welding, rolling, thermal exposure), structure changes both in local areas and in the entire volume. Changes in the steel structure entail changes in its properties and as a result in local areas, at various stages of operation, the likelihood of the occurrence and development of critical defects increases. Its presence significantly affects the performance of the equipment, and leads to premature aging of the material and its failure. Precisely because the control of the mechanical properties of steel remains one of the urgent problems, new control methods are being developed. It is known that all properties of steel depend on the structure of the substance, however, studies on the effect of the dispersion of the structure under consideration on the mechanical properties are presented in an insignificant amount. Purpose: to analyze from a mathematical point of view the influence of the factor of different grain size, as a parameter reflecting the dispersity of the system, on the mechanical properties of structural steel. The paper studies a heat-treated planar samples of steels 15KhSND, 09G2S and St3. Methods of research: scanning electron and optical microscopes are used to study the grain structure and grain boundaries; SIAMS 700 software package is used for finding the boundaries and average data of the grain structure; portable X-ray fluorescence analyzer of metals and alloys X-MET 7000 is used to determine the chemical composition of the test samples in percentage; tensile testing machine IR-50 is used for measuring the tensile strength of samples; Vickers hardness tester is used to determine the hardness of samples. Results and discussion: it is found that there is a satisfactory correlation for the mechanical properties of structural steels (hardness and ultimate strength) and the grain size factor, which can be used to predict the hazardous states of structures and the operating time. The analysis of variance and regression of the detected dependencies is carried out. It is noted that the dropout of some values from the general regression dependence can most likely be associated with a decrease in the value of internal stresses as a result of a decrease in the distortions of the crystal lattice of steel occurring during heat treatment. It should be noted that the processes occurring and the degree of its influence on the properties of the structural steels under consideration can be different due to the presence of different amounts of alloying elements in the composition of the studied steels.

KARAKTERISTIK KEBULATAN TERHADAP PARAMETER PROSES PEMBUBUTAN PADA MATERIAL ST 42 MENGGUNAKAN METODE TAGUCHI DAN ANOVA

This research is about the roundness characteristics of the turning process parameters on St 42 material using the Taguchi and ANOVA (Analysis of Variance) methods. A cylindrical product requires a good roundness value to ensure its quality. One of the factors that determine the quality of these products is the machining process parameters. In this study, optimization of the turning process parameters using the Taguchi and ANOVA methods was carried out on the roundness characteristics of the workpiece. The workpiece used is Steel St 42. The lathe used is the Krisbow Precision Gear Head Machine 410X1000MM. After data analysis using the Taguchi method, the parameters with the optimum roundness value of 7.385 µm were 510 rpm spindle rotation, 1mm depth of cut, and coolant opening valve. The results of the ANOVA analysis show the percent contribution of each parameter, respectively, as follows: spindle rotation 26.97%, depth of cut 24.82%, and coolant 38.63%.

Pengaruh Media Arang Kayu Bakau Mangrove Dan Arang Kayu Asam Pada Proses Perlakuan Carburizing Terhadap Sifat Mekanik Baja Karbon ST-37

In the military field, tank is armored fighting vehicles that move using chain-shaped wheels. The tread of the tank chain is a component to tread and move so that it requires tougher properties on the surface and has ductile and tough properties on the inside and is more resistant to wear on the surface. The development of tank chain production materials is necessary for the independence of national defense and security as well as reducing dependence on imports. Imported tank chain hardness value 28 HRC or 286 HV.
 In this research, the objective of this research is to increase the surface hardness of the steel by carburizing the initial material, especially the low carbon steel ST-37. The carburizing treatment process is a method of adding carbon content in steel using solid media. The carbon media used were mangrove charcoal and tamarind wood charcoal using calcium carbonate (CaCO3) catalyst at a constant heating temperature of 900ºC, variations in holding time of 30 minutes, 60 minutes and 90 minutes, cooled rapidly with water media. Then performed an analysis of the effect of the type of wood charcoal on the mechanical properties of carbon steel ST-37. The results obtained will be applied to the tank chain tread production process.
 The results of the micro structure of martensite and the highest hardness value were found in the holding time of 60 minutes of mangrove charcoal media with the microstructure results of 63.8% martensite, 36.2% bainite and a hardness value of 453.1 HV. The highest toughness value is found in the holding time of 60 minutes of tamarind wood charcoal media with an impact price (HI) of 0.4345 J/mm2. The difference between the impact test results of tamarind charcoal media with mangroves is not too significant. The higher the martensite phase, the higher the hardness value. However, there is also a bainite phase which can increase the toughness of the steel which will be used as a tread chain production material.