A promising direction of development of out-of-furnace vacuuming processes of steel

Based on the clean steel production process flow of converter steelmaking, this paper proposes a design method for process flow optimization, utilizing data analysis methods and numerical simulation for analysis and calculation. When applying this scheme, a process data analysis platform for converter steelmaking was created using machine learning and numerical simulation methods to identify the characteristics of process patterns from large-scale production data analysis. The newly proposed dynamic control scheme strategy is based on a model predictive control method, which combines the implementation of important process data information with process feedback, ultimately achieving dynamic adjustment of process parameters to enhance production efficiency. The results obtained from multiple experiments using this scheme and dynamic control methods ensure that the production cost of clean steel is reduced by 8.5% to 15.2% compared to when it is not used, and the production pass rate averages over 97%.During numerical simulation experiments, it was found that there is a relationship between the pressure of top-blown oxygen and the angle of the nozzle, and this relationship has a significant impact on molten steel temperature and decarburization degree. By comparing the production efficiency and energy consumption under different process parameter combinations, it was discovered that the use of a segmented dynamic control method not only improves various metallurgical parameters but also effectively reduces production fluctuations. The numerical simulation experiments demonstrated that this dynamic control scheme has high feasibility and strong practicality, providing an excellent solution for the production process of clean steel in converter steelmaking, with significant potential for widespread application.

The Impact of Major Macroeconomic Variables on Iran's Steel Import and Export

Steel production is one of the biggest emitters of greenhouse gas in the industrial sector with about 8% of total global CO2 emissions. Although the majority of emissions can be attributed to primary steel production, there is also potential for reducing CO2 emissions in downstream steel processing. Large industrial furnaces, which are necessary for heating steel, are currently primarily fired with natural gas and by-product gases from primary steel production, offering great potential for heat recovery measures from exhaust gases. However, switching to alternative climate-neutral fuels could change this potential and thus jeopardize the economic viability of heat recovery measures. In the present work, it was therefore examined to what extent a change in energy sources in industrial furnaces affects the potential use of heat recovery in steel processing. For this purpose, an optimization model was used that takes into account heat recovery by means of direct heat transfer, heat pumps and heat distribution systems. Potential future changes in energy supply for industrial furnaces were examined using different storylines. Two different energy price scenarios were also considered to address uncertain developments in energy markets. The results show that heat recovery is a cost-effective and definitely recommendable measure. Switching to alternative fuels has little impact on the use of heat recovery. Electrification and thus the elimination of flue gas, on the other hand, greatly reduces the potential for heat recovery.

To improve the utilization of steel scrap in the steel production process, the authors analyze the feasibility of adding scrap steel into the multifunctional ladle before hot metal tapping. Firstly, the authors provide an overview of the process. Secondly, theoretically study the melting process of scrap steel in the ladle along with the scrap steel melting mechanism is done. Finally, the effects of the addition of different types of scrap steel pretreated at various temperatures are examined using numerical calculation and simulation. The preheating temperature and specific surface area of the scrap steel had important effects on scrap steel melting. For the scrap steel with a specific surface area of 1.6 m2 t−1, the melting rate decreased by 4 min t−1 as the preheating temperature was increased from 300 °C to 800 °C. For a preheating temperature of 800 °C, the melting rate increased by 4.5 min t−1 as the specific surface area increased from 3.3 to 26.1 m2 t−1. Another 2.2%–6% of scrap steel can be added under certain conditions. This approach provides an effective solution to the problem of melting large amounts of scrap steel in steel works, further increases the utilization of scrap steel during steel production, and reduces the cost of steel production.

The water consumption intensity of steel production through BF-BOF technology was decomposed by an innovative process-based water-accounting model, i.e., water-balance model. One ton of steel product was chosen to be the functional unit. The system boundary of the case study included the production processes of coking, sintering, iron making, steel making, continuous casting and rolling. The results showed that the water consumption intensity of steel production was 3.969t/t in this case. The water consumption of evaporation, solidification and wastewater were 2.373t, 0.013t and 1.583t, accounting for 59.79%, 0.33% and 39.88% of the total water consumption, respectively. Steel rolling is the largest contributor to water consumption, and the amount of water consumption is 1.523t, accounting for 38.37% of the total water consumption; followed by coking process and continuous casting process, the amounts of which are 0.814t (20.50%) and 0.634t (15.97%), respectively. This finding can push the utilization of advanced technologies to save water resource in steel industry.

Video systems for production process coordination and assistance based on pattern matching are met in areas such as: production of electronic components and printed circuit boards, production of aluminum, steel and glass, automotive industry, agricultural industry and medicine and textiles. The defining element of video systems with industrial applications is the image matching algorithm used to identify the investigated item. Thus, for industrial video applications, the main purpose is to detect the defect region of the investigated images by comparing them with a reference image.

The industrial production of high-speed steel via continuous casting has been impeded by considerable technical obstacles, due to its high carbon content and fast cooling speed, which predispose it to severe segregation and poor high-temperature plasticity; thus, industrial continuous casting of high-speed steel is virtually nonexistent. In 2022, a curved continuous casting process was successfully applied in the production of M2 high-speed steel; in our previous study, it was found that the carbides were finer and better distributed in the billets by curved continuous casting than those in the billets by ingot casting. The change in carbides in the billets is significant in subsequent processes for M2 high-speed steel produced by curved continuous casting. Therefore, it is necessary to investigate the high-temperature tensile properties of M2 high-speed steel produced by curved continuous casting. In this paper, high-temperature tensile tests were conducted using a GLEEBLE-3500 simulator (DSI, located in New York State, USA) at different temperatures and holding times with a certain strain rate to obtain the tensile strength and reduction of area, and then the morphology of carbides near the fracture surface was observed. The results showed that the tensile strength and reduction of area increased with the increase in temperature at 850 °C to 950 °C, and there existed a temperature range between 950 °C and 1120 °C with good thermoplasticity and a reduction of area from 45% to 50%. In addition, a sharp drop in thermoplasticity below 5% occurred at 1180 °C, which is due to the significant growth of carbides. The zero-strength temperature and plastic temperature were 1220 °C and 1200 °C, respectively. In addition, with the increase in holding time at 1150 °C, the reduction of area increased from 34% to 54%, and the tensile strength decreased from 92 MPa to 70 MPa and then increased to 82 MPa. The best solution for carbides in M2 high-speed steel produced by curved continuous casting occurred when the range of the PHJ value was about 28.0 to 30.5. With the increase in PHJ value, the shape of carbides gradually changed from fibrous to short rod-like and blocky during high-temperature diffusion.

Iron preceded steel in the history of the metal industry. It was used for over three thousand years, and when the British settled in North America, the first iron works was set up at James town, Virginia, in 1621. By the time of the American Revolution, the colonies were producing one‐seventh of the world’s supply of pig iron at thirty thousand tons. Steel is made by alloying iron with carbon to produce a hard, strong metal. It was expensive to manufacture and the United States imported most of its steel until after the Civil War. The steam age provided much growth to the iron industry in the 1800s, with enormous demand for iron rails. Pennsylvania, with its large deposits of anthracite coal, was the nation’s leading state in the iron industry. Aided by the great iron ore deposits in the Great Lakes area and cheap water transportation, the production of iron and steel drove the Industrial Revolution, and the Mid west became the centre of American heavy industry. Developments in steel processing during the mid 1800s lowered the cost of steel production and allowed the use of steel for rail roads, construction, and other industrial uses. By 1883, approximately twenty years after the Civil War, the United States produced nearly 115,000 tons of steel and the Iron Age disappeared. The American steel industry continued to grow rapidly and by 1910 it produced more than 24 million tons, which was the greatest of any country. One of the high lights of the steel industry was the establishment of United States Steel Corporation in 1901 led by J. Pierpont Morgan and Elbert H. Gary. The corporation was valued at $1.4 billion and controlled more than 60 percent of the US market. The strength of America’s steel industry continued after World War II and peaked in 1969 at 141,262,000 tons. At this time, competition from steel plants abroad with lower labour costs and newer mills started edging in on the US market. By 1975, US steel production declined to 89 million tons, but rebounded slightly in the late 1980s (Gordon). The American steel industry would not be central to the economy as it had for the previous 100 years.

Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects) from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions – machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness). The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

The high carbon high chromium die steel is most widely used in various industrial applications. However, effective machining of high carbon-chromium die steel is extremely difficult due to its high hardness and stiffness. In the present work, comparative analysis of Gas Assisted Hybrid EDM (GAHEDM), Rotary EDM (REDM), and Conventional EDM processes have been done with respect to process responses like electrode wear ratio (EWR), material removal rate (MRR), and surface roughness (SR). Experimentation has been done to the study influence of process factors like discharge current, pulse on time, duty cycle, tool rotation and discharge gas pressure on MRR, EWR and SR. Further, from a comparative study, it has been observed that high MRR, low EWR and low SR are obtained in GAHEDM process in comparison of REDM and EDM processes. Analysis of surface morphology reveals that the formation of recast layer and cracks on the surface are fewer in number on work piece machined by GAHEDM process with respect to specimen machined with REDM and EDM processes. The results show that the use of compressed helium gas in GHEDM process has a positive impact on the machining performance. This process may be used for industrial machining operation.

The paper presents the results of research undertaken to investigate cold forming process for 40HM constructional steel suitable for heat treatment. In the first part of the paper, mechanical properties of this steel and its industrial applications are described. The second part of the paper presents the results of the analysis of flow curves for two kinds of steel specimens: those that were subjected to annealing and those that did not undergo any heat treatment. It was found that the application of heat treatment had a significant effect on improving the forming conditions for this steel at room temperature. The experimental flow curves obtained in a compression test were described by constitutive equations illustrating the dependence between flow stresses and strain value. In order to determine the equation coefficients, the Generalized Reduced Gradient method implemented in Microsoft Excel was used. Based on the obtained equations, a material model will be developed to perform numerical simulations of cold forming for 40HM steel, using FEM-based software that aids the design of metal forming technologies.

Porous three dimensional (3D) graphene macrostructures have demonstrated the potential in versatile applications in recent years, including energy storage, sensors, and environment protection, etc. However, great research attention has been focused on the optimization of the structure and properties of graphene-based materials. Comparatively, there are less reports on how to shape 3D graphene macrostructures rapidly and effortlessly, which is critical for mass production in industry. Here, we introduce a facile and efficient method, low temperature frying to form graphene-based spongy balls in liquid nitrogen with a yield of ~400 balls min−1. Moreover, the fabrication process can be easily accelerated by using multi pipettes working at the same time. The graphene spongy balls show energy storage with a specific capacitance of 124 F g−1 and oil adsorbing with a capacity of 105.4 times its own weight. This strategy can be a feasible approach to overcome the low efficiency in production and speed up the development of porous 3D graphene-based macrostructures in industrial applications.

Positioning systems play an important role in industrial and scientific applications, making their performance improvements and functional expansions crucial. Positioning systems generally consist of mechanisms, actuators, controllers, and sensors, with performances and functions depending on their integration. Accordingly, positioning technologies focus on these elements and their integration into the system. Actuators are fundamental and critical elements that characterize positioning systems. Electromagnetic actuators are the most widely used because of their high basic performance, and piezoelectric actuators are often used for fine movement. In addition, research on new actuators with unique characteristics is actively being pursued. In component integration, control technology plays a crucial role in effectively utilizing the characteristics of elements and addressing their drawbacks. With the recent advances in digital technology facilitating nonlinear representations and structural modifications, various control methods have been proposed and evaluated to benefit from these advances. In addition to proposing modeling methods, the effects of manufacturing processes on system performance have been evaluated. This special issue contains 18 papers covering the design and characteristics of mechanisms and actuators, control technology, system design, and modeling, along with three review papers on positioning technology and its applications. We would like to express our sincere gratitude to the authors for their excellent contributions to the special issue. We also thank the reviewers for their incisive efforts in editing this special issue. We hope that this special issue will help readers enhance their knowledge and understanding of positioning technology and its applications, thereby contributing to its progress.

It is not quite uncommon, in general, to use DC motors in industrial applications, but after the introduction of power electronics, AC motors grabbed much importance. Of these, induction motors are widely used in industrial and domestic applications due to the advantages like simple construction, ruggedness, flexible control, good efficiency and low cost. In order to control the stator voltage and speed, PWM inverters are used. But the usage of PWM inverters has the effects like non-uniform voltage distribution and increase in the temperature. Recent advances in power electronic switching device technology have resulted in dramatic improvements and cost reduction of pulse-width modulated AC adjustable speed drives. Concomitant with the better performance enabled by the high switching speed and increased switching frequency they have also raised several concerns related to the consequences of high speed switching. One of these concerns is the over-voltage that appears at the motor terminals due to the impedance mismatch between the power cable and the motor. In this paper a developed accurate simulation models for power cables and motors that allow a better understanding of the over-voltage problems. The models can be readily implemented using computational tools like MATLAB, thereby providing a convenient method to develop the best dv/dt filter solution for a particular drive. The power cable is modeled using several lumped-parameter segments of a lossy representation of transmission line. An algebraic analysis is developed to choose an adequate number of lumped-parameter segments. The number of required segments is a function of the pulse rise time, cable characteristic parameters and cable length. Simulation results are presented analyzing the over-voltage problem for a wide range of cable lengths for 3 hp, 15 hp and 40 hp motors. The most important filter networks are also designed and the solutions are investigated using the simulation programs.

The Montreal Protocol established stringent international regulations concerning the production, consumption, and trade of ozone-depleting substances, including chlorofluorocarbons and hydrofluorocarbons, aimed at safeguarding the Earth's ozone layer. In this context, cyclopentane has emerged as an environmentally sustainable alternative owing to its zero-ozone depletion potential and low global warming potential. This review examines the physicochemical properties, industrial applications, and production methods of cyclopentane, with particular emphasis on its utilization as a refrigerant, a blowing agent in rigid polyurethane foams, and a hydrate-forming agent for seawater desalination. The primary applications are concentrated in refrigeration and thermal insulation, where cyclopentane-based foams demonstrate superior thermal conductivity and mechanical stability relative to conventional agents. However, the flammability of cyclopentane vapor presents operational challenges that necessitate the implementation of appropriate safety measures. Advances in catalytic reaction-distillation and extractive distillation processes may improve the efficiency of cyclopentane production and product purity in industrial settings. This review underscores cyclopentane’s efficacy as a substitute for compounds with higher ozone depletion potentials and emphasizes the importance of ongoing research into scalable, economically viable production technologies and safe industrial integration to fully realize its environmental and practical benefits.