Various Grades Of Steel Research Articles

Study of the impact of TIG welding parameters and post-weld heat treatment on the bending properties of AISI 1020 steel welded joints

Tungsten Inert Gas (TIG) is a welding technique that stands out due to its high precision, controlled heat input, and equipment’s cost-effectiveness. TIG welding is utilized to join various grades of steel. Presently, numerous research studies are actively seeking to improve the quality of welded joints, focusing on aspects such as strength, ductility, formability, appearance, and corrosion resistance. These improvements are achieved through the modification of welding methods and/or welding parameters. In this investigation, welding current and gas flow rate were selected as input parameters. Additionally, PWHT at 700 °C for 1.5h was applied to relieve the residual stresses occurring during the welding operation. The objective of this investigation is to examine how the welding current, gas flow rate, and post-weld heat treatment (PWHT) affect the bending properties of welded joints. The bending test was conducted to assess both the bending resistance and bending strain of the joints. The bending resistance increases to attend a maximal value of 790 N and the bending strain decreases to 7.1%, with the welding current and the gas flow rate due to the high heat input and cooling rate. The applied PWHT decreases the bending resistance by 11% and increases the bending strain by 18%, due to the decrease of the joint’s hardness.

Load-end shortening curve of stiffener elements with beam-column buckling considering steel grades based on empirical formulae of critical stress

The existing load-end shortening formulae with beam-column buckling in CSR-H were derived from the theoretical buckling formulae of stiffener elements considering the effective width of attached plate. However, due to different yielding stress and plastic flow ability, the critical stress of stiffener elements for elastic-plastic beam-column buckling may be relevant to steel grades. The critical stress of beam-column buckling was analysed by numerical method and compression test under supply supported constraints. Separate seven steel column samples from slender to sturdy were designed to be studied for various grades of steel mainly including 921A, S355 and Q235. After comparison, the empirical formulae of critical stress considering different yield stress were proposed in power exponent expression, and then employed to replace the theoretical buckling formulae in the load-end shortening curves in incremental-iterative method. This new load-end shortening expression of stiffener elements with beam-column buckling mode could more accurately evaluate the progressive collapse behaviours under longitudinal compression.

Atomistic structural transformation of Fe-Cr-Ni single crystal alloy under uniaxial deformation using molecular dynamics simulation

The evaluation of mechanical properties, microstructure, and phase transformation of Fe-Cr-Ni alloy under different strain rates, at temperature 300 K has been done in this investigation, using molecular dynamics simulation. These properties are of utmost importance, for the design and development of different grades of metals and alloys. In this study, a nano-size face center cubic (FCC) single crystal of Fe-Cr-Ni alloy has been selected to examine stress–strain response under various strain rates at room temperature through molecular dynamic simulation. In this simulation study, It was found that, the evolution of an alternate multilayer stack of a rectangular block of face center cubic (FCC) atoms, hexagonal close pack (HCP) rectangular block atoms and strain induced martensitic phase transformation occurred during uniaxial loading at a strain rate of 1011 s−1 at ambient temperature. It was also observed that the intersection of stacking faults is a source of dislocation. This study based on MD simulation provides an in-depth concept of the mechanical properties during mechanical and thermal processing. It also helps improve the mechanical properties of various grades of steel and other engineering materials.

An Overview of Microbiologically Influenced Corrosion on Stainless Steel

AbstractDue to its excellent resistance to corrosion, stainless steel has a broad employment scope in oilfields. It is defenceless against microbiologically influenced corrosion (MIC). Here, organisms directly cause corrosion. Microorganisms release disruptive metabolites or organisms collect electrons from the metal for breathing to produce energy. They are responsible for the onset or escalation of corrosion caused by previously existing detrimental specialists such as water and carbon dioxide. However, only a few reports on their real success against MIC have been published. Numerous studies on stainless steel, in the presence of microorganisms, are discussed. An analysis of microbiological contamination is also detailed. It focuses on the general perspectives of the various microscopic species involved in biocorrosion. A review on this topic is necessary to understand the various factors considered to select a certain material for a specific purpose. This article combines the various grades of steel, their applications, their studies, and results all in one view making it easier for the reader to understand the importance of microbially influenced corrosion.

Optimization of product processing modes in modeling and programming of machining on machine tools with program control

Purpose. To solve a scientific and technical problem related to the technological support of high-performance machining of a cast iron part by optimizing and controlling its machinability with a hard-alloy tool on multi-axis CNC machines using CAD-CAM systems. The methods. The methodological basis of the work is a systematic approach and analysis of the study of the object of research, based on the use of: numerical and graphical-analytical research methods in order to establish a systematic relationship between turning parameters and the properties of the material being processed, tool geometry and its stability, parameters of cutting modes with the corresponding indication in the control program for the CNC machine. Findings. Numerical research results have been obtained for a scientifically based approach to solving the technical problem of high-performance turning of cast iron parts on multi-axis machining centers, which contains a set of adjusted methods and algorithms for predicting their machinability with ensuring the reliability of hard alloy cutting tools. The results obtained were compared with known works related to the study of machining processes of various grades of steels, alloys, and cast irons, the assessment of the reliability of cutting tools, the accuracy and roughness of the machined surface, and the results of measurements of cutting force parameters. The maximum relative error of the calculations did not exceed 6-8%. The originality. Establishment of a complete and systematic connection of machining parameters with the properties of the processed material, tool geometry and design and technological factors of the part for the calculation of an optimized automated production technology. In the mathematical and statistical processing of experimental data, which made it possible for the first time to obtain complex dependencies in a form convenient for calculation and analysis, which give a clear picture of the effect of each parameter of the turning process on its energy and time indicators when compiling a rational technology for machining a part of complex geometric shape in a CAM system. Practical implementation. It consists in selecting and justifying the optimal geometric parameters of cutting tools and equipment, establishing the nature of the influence of the conditions of turning cast iron on the main process parameters - machining time and operating parameters depending on the hardness of the part material and tool material. Practical recommendations are given on the optimal use of CAD-CAM systems, adjustment of process results and operating parameters to obtain optimal results at the stage of production preparation.

Numerical Simulation of Mechanical Joining of Three DP600 and DC06 Steel Sheets

There are many reasons to utilize various grades of steel in car body production. Automotive producers tend to choose steels with great formability and the capacity to absorb impact energy. The dominant method used for joining car body sheets has for many years been resistance spot welding, but the use of various steel sheets leads to research into alternative joining methods. Mechanical joining - clinching, is the innovative method to join these materials. Numerical simulation tools are used to optimize the joining of materials. Simufact Forming software was used to analyse the clinching joining of three sheets of material DP600 and DC06. According to the axisymmetric character of the mechanical joining process, the simulation was stream-lined to a 2D representation. The results of the simulation of the mechanical joining process were compared with the real samples prepared for metallographic observation.

Mechanical and tribological characteristics of laser-deposited nickel-containing powders on chromium steels

This paper presents the results of a study of various processing modes during the laser surfacing process. Various grades of steel were used as samples, and the resulting coatings were based on two grades of powders. The microhardness values were obtained both for the main steel material and for the coatings obtained on the samples. The values of the friction coefficients of the coatings are obtained, on the basis of which the graphs of standard deviations are constructed. The results are summarized using graphs and figures.

WELDING OF S355J+N LOW ALLOY STEEL ELEMENTS IN RAILWAY CARRIAGES STRUCTURES

Various types of structures and materials play an important role in the creation modern means of transport, including various grades of steel with different mechanical properties. For the rolling stock, proper operation and meeting the operational conditions is very important. Welded structures play an important role in the construction of various means of transport. Correct welding of carriages is important both in production and when carrying out various types of repairs. Each repair a carriage depends on its advancement and condition and the time of its operation. Each inspection for a refurbished carriage is defined either by the service life or the big distance traveled by the carriage. Important factor that may lead to damage is the effect of the load transported in the carriage. Therefore, the causes of the wear of the rolling stock are investigated and measures are taken to prevent any damage. The appropriate technical condition of the carriage also ensures safety on railroads for users and owners of the rolling stock. In the case of welded structures in carriages, it is influenced by poorly materials choice, incorrectly selected production processes and wrong selection of parameters. The goal of this paper is the mechanical properties analyse of weld low alloy steel structure of carriages after MAG welding using the parameters of the process. Thick-walled steel structures are used to build carriages, which is often a serious welding problem. The main role of welding conditions is connected with filer materials, welding technology, state of stress and temperature. In this paper, the properties of low alloy steel S3555J+N structures after MAG welding are presented. Furthermore, metallographic structure, tensile strength, bending test and impact toughness welded joints were analysed regarding welding parameters. The amount of acicular ferrite in WMD oxygen after welding was tested. Gas mixtures of argon and carbon dioxide with various percentage was used for shielding gas.

A Review on Steels for Cryogenic Applications

Abstract Cryogenic systems have played a crucial role in almost all of the finest technological achievements of mankind. Cryogenic applications demand materials with a unique combination of properties, which drastically limits the choice of materials. In most other engineering applications, because of wide tailorability of their properties and excellent combination of strength and toughness, coupled with lower cost compared with nonferrous materials, steels have become the preferred/dominant structural material for cryogenic applications. The contradictory requirement of higher strength without compromising toughness at cryogenic temperatures posed considerable challenges and led to the development of large array of steels tailored for specific applications. This review is an attempt to survey the metallurgical aspects, material selection, mechanical property evaluation, and application of various standard and nonstandard steels for cryogenic applications. This review covers the influence of low temperatures on material properties, simulative mechanical tests for property evaluation, metallurgy of steels, and application examples surveying the published literature to date. The review also analyzes the origins of low-temperature toughness, various application requirements, and the work carried out at authors’ laboratories. The issues pertaining to mechanical tests at low temperatures and status of data generation in international scenario have been critically analyzed. Physical metallurgy aspects have been highlighted in the review, and microstructure-property-processing correlations for various steels have also been covered. One of the recent advances in steels for cryogenic applications, high-entropy alloys, which are proposed as alternatives for the conventional steels, have been reviewed, and mechanical property data have been critically analyzed. The potential of additive manufactured steels for low-temperature applications has been reviewed. Finally, this review article discusses challenges in processing–mechanical properties correlation for various grades of steels for cryogenic applications. It also provides useful information for researchers working on steels for cryogenic applications with a glimpse of recent advances made in this area.

Numerical Modelling of Round Bars Rolling Process in Three-High Skew Rolling Mill HDQT-R 30-12

In the 21 st century, numerical analysis is a proven tool for research and development of manufacturing processes. Mathematical modelling provides information about the behaviour of various materials during forming processes, for instance. The real-world process is therefore represented by an abstract mathematical model, on which calculations are performed. Three-roll skew rolling can be used for various grades of steel. This paper presents the results of a theoretical analysis of skew rolling of bars with an initial diameter of 30 mm for three different carbon steels, S235JRC, C45 and C60, and austenitic stainless steel AISI 321. The final diameter of the rolled bars was 22 mm and was achieved in a single pass. Several different rolling speeds were used for the stainless steel. The simulations were carried out using DEFORM 2D/3D software. The behaviour of the materials during rolling was analysed, including the values of effective strain and stress.

Manufacturing of cylindrical articles with a thick bottom and thin wall

The issue of increasing the efficiency of metal forming processes by combining the operations of drawing with thinning of the wall and extrusion in the manufacture of cylindrical articles having a thick bottom and thin wall. The ratio of height to diameter can vary from 1 to 10 and more. These are various connectins, adapters, unions, elements of cases, sleeves and other articles with a wall thickness less, than thickness of a bottom. Rolled sheet metal made of various grades of steel, brass, aluminum, titanium and other materials can be used as workpiece materials. The combination of drawing operations with wall thinning and extrusion at one working position allows to significantly expand the technological capabilities of metal forming, reduce the number of steps, improve the quality of articles. Compared to backward extrusion, the proposed technology provides a lower level of stress in the tool and workpiece, enabling to use less powerful hydraulic press equipment and significantly increase the durability of stamping equipment. When using blanks with planar anisotropy, this technology allows not only to eliminate earing on the edge surface of the semi-finished product and get a smooth face end of the product, but also to form any other profile of the edge of the part. The formation of articles without earing eliminates the operation of trimming the end face of the semi-finished product, which significantly increases the utilization of the material and reduces the cost of finished articles. The method for calculation of geometrical parameters of stamping equipment to obtain defect-free articles is given. Theoretical studies of the combination of drawing operations with thinning and extrusion of the cylindrical workpiece were carried out by the finite element modeling method using the QFORM software package. The scheme of universal experimental stamping equipment is shown.

Multi-Response Optimization of Parameters using GRA for Abrasive Water Jet Machining of EN31 Steel

A wide variety of materials are used in the automobile industry that includes casting tools, dies, studs, nuts & bolts, bearings, and punches, etc. These require high hardenability, great toughness, more strength, and good resistance to thermal shocks. Among various grades of steel, the EN31 fulfills all these qualities efficiently. But, due to its high hardness and strength, conventional machining of EN31 is not economical. Among various non-conventional machining processes, abrasive water jet machining is employed when there is a necessity for high surface finishing & fast cutting. This paper includes the machining of EN31 steel with an Abrasive Water Jet Machine. In this work, Pressure, Abrasive Mass Flow Rate, Standoff Distance & Traverse Speed (Quality) are considered as parameters, and hence their effects on the responses like Machining Time, Surface Roughness & Hardness are studied. With Grey Relational Analysis, all the selected parameters are optimized for; minimum machining time, minimum surface roughness & maximum hardness. The approach is used to obtain Grey Relational Grade (GRG) and hence the optimal solution is obtained.

ANALYSIS AND PREDICTING THE ACCURACY OF PIPES AT SINKING

Pipes are subjected to free drawing after short-length drawing or rolling on cold rolling mills, that is, pipes that have a certain wall thickness difference. In order to assess the accuracy of pipes after non-dragging, technological routes for the production of pipes from various grades of steels were designed and investigated. Batches of pipes were pulled along the developed routes according to the production technology, samples were taken from each batch, and the wall thickness was measured at equidistant points of the pipe cross-section. Based on the measurement results, a correlation-regression analysis were performed, the factors influencing the change in wall thickness were determined, and regression models were built. The intensity of the correction depends on the coefficient of reduction in diameter, the greater the value of the ratio of the initial diameter to the final diameter of the pipe, the more intensive the correction of the wall thickness. That is, in order to correct the difference in wall thickness during uncorrected drawing, it is necessary to increase the stretch ratio. With a small wall thickness difference of the work piece (less than 3%), the wall thickness difference of the finished pipes increases, with a work piece wall thickness difference of 3 ... 4%, the wall thickness difference of the finished pipes changes little and at δ0 > 4%, the wall thickness difference of the finished pipes decreases.When analyzing the dependences obtained in the work, some conclusions can be drawn: the more ductile the metal, the less the change in wall thickness. Less ductile steels have a greater tendency to change the wall thickness. At low values of the relative wall thickness difference of the work piece, the coefficient of change in wall thickness reaches 3.5, that is, the wall thickness difference increases by 3.5 times, and at large values of the relative wall thickness difference of the work piece, its correction is more intensive. The intensity of the correction depends on the coefficient of reduction in diameter: the larger the value of the reduction, the more intensive the correction of the difference in wall thickness. That is, in order to correct the difference in wall thickness during uncorrected drawing, it is necessary to increase the stretch ratio.

STUDY OF THE INFLUENCE OF THE CARBON CONTENT IN STEEL ON THE STRUCTURE AND MICROHARDNESS OF THE SURFACE LAYER AFTER ELECTROMECHANICAL PROCESSING WITH IMPACT

Experimental data of metallographic and x-ray diffraction studies of the surface layer of various grades of steels subjected to electro-mechanical processing (EMO) with dynamic (shock) application of the deformation force are presented. The influence of the carbon content in steel on the formation of the structure, microhardness and depth of hardening of the surface layer obtained in the field of pulsed temperature-force action is considered.

Modelling and Simulation of Below-the-Hook Lifting Device Balanced C-hook for Load to Investigate the Static and Model Analysis for Various Grades of Steels by Numerical Method

Below-the-Hook Lifting Devices will enable easy loading, unloading and transportation of heavy metal coils. A balanced c-hook is one of the widely used Below-the-Hook Lifting Devices works by inserting its lower arm inside the hole of coil. Multiple variations of c hooks are being used based on different load requirements, and different applications like paper roll c hooks to transport heavy paper rolls, spring loaded c hooks to reduce weight by avoiding counter weights etc. Structural and mechanical lifters may be modified or re-assessed, provided that such alterations are analyzed and approved. Balanced c-Hook are to be designed by considering forces imposed by the lifted load, the weights of the device’s parts, since balanced c hooks are subjected repeated loading and unloading, there is probability of failure due stress concentration. To prevent chances of failure, Prior study is required on this; the materials which are generally used for the C hook are considered for a particular loading condition of 10 Tons, Design of the bellow the hooks is done by numerical method. Modeling and Simulations are carried to determine the various factors like deformation, stresses generated and mode shapes. The comparison among all the selected materials is done to check the suitability of the material to use as a balanced C hook. For the generation of CAD model of C -Hook various geometrical features and Dimensions are selected as per the specification from ASME B30.20 standard. To investigate statics stress results and model are obtained from Finite element Method. from the results of the analysis it is observed that results obtained are in close match with each other and maximum stress concentration occurs at inner most surface.

ASSESSING THE INFLUENCE OF EXTRACTED FLUID AND OPERATIONAL CONDITIONS ON CORROSION OF GAS FIELD EQUIPMENT

Background The main intensifier of corrosion at the objects of the studied oil and gas condensate field is carbon dioxide corrosion (CDC). Aims and Objectives Based on the data from well surveys, analyze the factors affecting the corrosiveness of the media: CO2 partial pressure, temperature, reservoir pressure, pH, salinity, and water composition. After compiling the ion balance and recalculating it to the salts used in the manufacture of model solutions of the salts, make up three model waters corresponding to individual and mixed formations for further testing. Results The main danger in CO2 presence is not general, but local corrosion occurring in the fluid flow under conditions when FeCO3 films, although formed, but at low temperatures characteristic for the studied field, they are not stable enough. The appearance of a crack in the FeCO3 film initiates its cleavage, at this point the CDC begins, creating a carbonate film, which with a certain thickness cracks and chips. Some erosions are formed within the other of corrosive areas. Such local corrosion damages are developing, leading to deep (or through) pitting, to damages occupying the big area in interconnection of separate local corrosion defects on an internal surface of elements of a wellhead. Calculations of corrosion damages depth on a flange from a wellhead after removing the corrosion products testify that corrosion depth damages are from 1.0 to 2.5 mm. As the inspections show, the damages made by CDC are observed not only on a well head, but also in pump-compressor pipes of the wells. Operational tests of various grades of steel in the well media, characterized by high CO2 content (up to 1.7 %), showed that most of them are unstable to CDC, with except the alloy steel 12X18N10T. The rate of general (uniform) corrosion reaches several mm/year, including the low-alloy steel 09G2C used for most elements of the wellhead.

BASIC APPROACHES TO THE CHOICE OF MATERIAL FOR WORKING BLADES OF THE LAST STAGES OF THE LPC OF POWERFUL STEAM TURBINES

The paper outlines the need for a comprehensive analysis and selection of steels for the working blades of the last stages of low pressure cylinders (LPC) of high-power steam turbines. The authors reviewed the criteria and exist-ing technical requirements for the materials of the working blades. The analysis of various grades of steels for low-pressure cylinder blades was carried out taking into account the experience of their production at JSC “Turboatom”. The proposals on the use of materials of working blades with a large length of the active part are given, as well as ways for further research are outlined.

Investigations into the wear rate of conical picks with abrasion-resistant coatings in laboratory conditions

As part of own works performed by the Department of Machine Engineering and Transport of AGH University of Science and Technology, investigations into the rate of conical picks’ wear were carried out. For this purpose, the previously developed methodology for running experiments at a specialist laboratory test stand was applied. Tests were carried out for a total of seven types of conical picks with the same geometric parameters, but made of various grades of steel and with the body working surface covered by abrasion-resistant materials. The conducted investigations and the analysis of results allowed recommending conical picks made of S235 steal and hardfaced with EP-TB-1-6 or EP-TB-2-46 electrodes. However, it seems advisable to continue attempts aimed at finding a protective coating for the body of the pick.

Abnormal mold level fluctuation during slab casting of peritectic steels

Abnormal mold level fluctuation is frequently observed in high-speed casting, especially for peritectic steels, which has been shown to severely deteriorate product quality. Both an online electromagnetic sensor and an ibaAnalyzer are used to analyze the frequency and amplitude of massive mold level fluctuation data from the slab casting process of different steel grades using different casting speeds, slab widths and physical parameters of mold flux. The results show that in the slab continuous casting process of peritectic steels, the main frequency and equivalent amplitude of abnormal mold level fluctuations first increase and then decrease with increasing the carbon content. In the production of various grades of steel, the main frequency of abnormal mold level fluctuation and the equivalent amplitude increase with increasing the casting speed, while the main frequency of abnormal mold level fluctuation changes little with increasing the casting width. The main frequency of abnormal mold level fluctuation is positively related to the surface tension of the mold flux. Based on these results, a new mechanism has been presented. It is shown that the abnormal mold level fluctuation is mainly induced by shell bulging while moving through the rollers, and resonance occurs when the frequency approaches the natural frequency of the molten steel in mold, which results in a large amplitude of the abnormal mold level fluctuation. Based on this mechanism, a new equation for the resonance frequency of molten steel is proposed. The improved method based on this mechanism has proved to be effective in controlling abnormal mold fluctuations.

Hardness and Microstructural Behavior of Normalized Steel-Welded Joint under Varying Temperature

The effect of normalizing on a weld joint and heat affected zone of various grades of steel with known composition were estimated. Microexamination of samples was also done on the steel containing 0.22 wt % C to 0.36 weight percent of carbon. after normalizing at 7000C, 8000C and 9000C respectively. From the results, significant microstructural modifications due to heat treatment were noticed. The as- rolled 0.22 %C and 0.24 %C respectively consist of little pearlite regions in ferrite matrix. While the 0.36 %C consist of uniformly distributed pearlite regions (dark) in ferrite matrix (white) especially at austenization temperature of 8000C and 9000C above the upper critical temperature for all the steel grades. While those normalized at 7000C were fine pearlites, with varying amounts of spheroids of ferrite nucleated within the matrix.