Iron And Steel Research Articles

The Influence of Employee Productivity and Operational Costs on Increasing Revenue PT. Diamond National Iron Industry Medan

This research aims to analyze the impact of employee productivity and operational costs on income growth at PT. Intan National Iron Industry Medan. The study uses multiple linear regression methods with a sample of annual financial reports from the past six years, which have been approved by the company leadership. The motivation for this research stems from fluctuations in income over the years, particularly during the pandemic, where a drastic decline was observed. The income generated was insufficient to cover operational costs, leading to unmet income targets and a lack of management incentives, or even company losses. The results of the study indicate that employee productivity has a positive and significant effect on income, with a T-value of 7.079 (T-value 7.079 > T-table 2.015) and a significance level of 0.000 < 0.05, meaning that Ha is accepted and H0 is rejected. Operational costs also have a significant impact on income, with a T-value of 3.976 (T-value 3.976 > T-table 2.015) and a significance level of 0.000 < 0.05, again leading to the acceptance of Ha and rejection of H0. Furthermore, the combined effect of productivity and operational costs yields an F-value of 34.852 > 4.74 with a significance level of 0.000 < 0.05. These findings demonstrate that both employee productivity and operational costs positively and significantly influence income growth at PT. Intan National Iron Industry Medan.

Partisi Ruang Berdasarkan Kebutuhan Pengguna Dengan Konsep Industrial

Along with the development of the era, human desires for housing are increasingly diverse, where houses are not only for carrying out daily activities and carrying on life, but also become a means of inspiration and indicate social levels in the community. The design object to be appointed is the residence of Mr. Antok Suharno which is located in the village of Mulyorejo, Mojosongo District, Boyolali Regency. The residence previously did not have a concept, the Industrial concept became the design theme plan to be implemented. The design objective is to create privacy for the living room and dining room that meets user comfort in accordance with the comfort theory by presenting a partition, functioning as a separator as well as maintaining privacy and presenting decorative value between the living room and dining room. The data collection method is by surveying, measuring and documenting the location of Mr. Antok Suharno's residence, collecting user data for each room and interviewing Mr. Antok Suharno as the owner of the house. Partitions designed to apply materials in accordance with the Industrial concept, namely with black hollow iron material, multiplex and vinyl finishing with wood motifs. The results of the partition design have a length of 180cm, a width of 30cm and a height of 200cm.

Пути повышения конкурентоспособности российских металлургических компаний

The authors explore ways to improve the competitiveness of Russian metallurgical business on the example of two leading companies in the industry - PJSC Severstal and PJSC Magnitogorsk Iron and Steel Works. The article analyses the strategies, financial results and methods used by these companies to strengthen their market positions, including investments in production modernisation, the introduction of innovative technologies, the development of strategic partnerships and a focus on environmental sustainability. The key highlights and achievements of each company are discussed, as well as their contribution to the development of the Russian steel industry. The article concludes by highlighting the key factors contributing to successful competition in the global market and offers recommendations to further improve the competitiveness of the Russian metallurgical complex.

Пути повышения конкурентоспособности металлургического комплекса России

The authors explore ways to improve the competitiveness of Russia's metallurgical complex on the example of two leading companies in the industry - PJSC Severstal and PJSC Magnitogorsk Iron and Steel Works. The article analyses the strategies, financial results and methods used by these companies to strengthen their market positions, including investments in production modernisation, the introduction of innovative technologies, the development of strategic partnerships and a focus on environmental sustainability. The key highlights and achievements of each company are discussed, as well as their contribution to the development of the Russian steel industry. The article concludes by highlighting the key factors contributing to successful competition in the global market and offers recommendations to further improve the competitiveness of the Russian metallurgical complex.

Experimental investigation and CFD study of direct reduction of iron ore in the conical fluidized bed

The reduction behavior of iron ore is the fundamental process in ferrous metallurgy. Considering the gas–solid interface-structure relationship, heterogeneous transfer-reaction behavior, and multiple reaction kinetics, this work provides an effective analytical tool to investigate the fluidized reduction of iron ore. The conical fluidized bed is numerically examined to be capable of preventing de-fluidization induced by the sticking behavior, due to the steady circulation of flow pattern and full fluidization of coarse agglomerates. Compared with the hydrogen concentration, the gas velocity shows a stronger influence on the agglomerate reduction rate for the more efficient gas–solid contact. For the simulated transitions of Fe2O3 → Fe3O4 → Fe(1-x)O → Fe are assumed to overlap each other, there exist discrepancies between computed and theoretical reduction degrees. The experimental and numerical findings can be used to develop a methodology for optimizing the operational complexity and economic benefits of the fluidized reduction of iron ore.

Physico-chemical characterization of cupola slag: Enhancing its utility in construction

Cupola slag is a waste material of the steel and iron industries. Its composition is determined by the cupola furnace and other elements used in steel and iron manufacturing. This paper investigates the characterization behavior of various cupola slag materials. As a result, x-ray fluorescence (XRF), x-ray diffraction (XRD), thermogravimetry differential thermal analysis, and scanning electron microscopy (SEM) methods were used to characterize three cupola slag samples from distinct origins. In addition, various physical properties were used to compare different cupola slags. The specific gravity values of CS-1 (cupola slag-1 sample), CS-2 (cupola slag-2 sample), and CS-3 (cupola slag-3 sample) are 1.36, 2.5, and 2.917, respectively. The density and water absorption for CS-1, CS-2, and CS-3 are 1414.86, 1477.71, and 1796 kg/m3, and 0.37%, 0.32%, and 0.26%, respectively. Cupola slag also includes a larger percentage of lime, according to XRF data, which contributes to its improved binding characteristics. A higher calcium oxide content in CS-3 could facilitate the pozzolanic process. The presence of angular particles that aid in material binding is seen in the SEM image. Compounds with a nanostructure are then flawlessly blended into the mixture and grouped with calcium alumina silicates formed by cement hydration. The XRD pattern of cupola slag exhibits high peaks, indicating that the material is crystalline in character and can be utilized as sand. It also shows the presence of other chemical compounds, such as silica, which ranges from 30% to 45%. CS-1 and CS-2 have comparable XRD patterns. However, CS-3 has a somewhat different pattern because of the greater CaO content. Weight loss begins at higher temperatures, which shows that the material is stable at higher temperatures, according to a thermo-gravimetric study. The differential thermal analysis curve of CS-3 indicates that the material remains stable up to a temperature of 600 °C. The physical characteristics of all cupola slag samples show that cupola slag may be utilized to make sustainable building materials because of its lower specific gravity, density, and water absorption.

A Comparative Analysis of Friction and Energy Losses in Hydrogen and CNG Fueled Engines: Implications on the Top Compression Ring Design Using Steel, Cast Iron, and Silicon Nitride Materials.

Optimizing the design of the top compression ring holds immense importance in reducing friction across both traditional Internal Combustion (IC) engines and hybrid power systems. This study investigates the impact of alternative fuels, specifically hydrogen and CNG, on the behavior of top piston rings within internal combustion (IC) engines. The goal of this approach is to understand the complex interplay between blow-by, fuel type, material behavior, and their effects on ring friction, energy losses, and resulting ring strength. Two types of IC engines were analyzed, taking into account flow conditions derived from in-cylinder pressures and piston geometry. Following ISO 6622-2:2013 guidelines, thick top compression rings made from varying materials (steel, cast iron, and silicon nitride) were investigated and compared. Through a quasi-static ring model within Computational Fluid Dynamics (CFD), critical tribological parameters such as the minimum film and ring friction were simulated, revealing that lighter hydrogen-powered engines with higher combustion pressures could potentially experience approximately 34.7% greater power losses compared to their heavier CNG counterparts. By delving into the interaction among the fuel delivery system, gas blow-by, and material properties, this study unveils valuable insights into the tribological and structural behavior of the top piston ring conjunction. Notably, the silicon nitride material demonstrates promising strength improvements, while the adoption of Direct Injection (DI) is associated with approximately 10.1% higher energy losses compared to PFI. Such findings carry significant implications for enhancing engine efficiency and promoting sustainable energy utilization.

Design of a welding table as a medium for determining elbow points and joints

Welding is a method of joining two or more metals with electrode extension media using current heating and voltage according to the variation in the thickness of the iron material used. Welding is one of the connection media with a patent system, meaning that the results of the process can be changed by damaging the results of the welding process. From looking at several welding workshops, almost all of them to do welding are under or on the ground so many workers complain that they tend to be more tired and the welding results are less than optimal, especially for symmetrical or straightness of the connection results. The method used in this research is to design a welding table that is adjusted to the level of needs, especially for the height of the table and the centric axis to combine so that the results of the connection process are completely straight and reduce the results of welding defects. The purpose of designing this welding table is to use it as a method for working on the welding process so that the welding results are really strong and straight according to the design drawing. From the results of the design process, a welding table is obtained with iron material as a table base to place the workpiece to be cut. using borders of iron with a thickness of approximately 120 x 240 x 40cm using Material: Iron plate about 5-6 mm thick. In addition, the results of the design process also reduce the welding process time for blunt joints from 85 seconds to 48 seconds, overlap joints from 85 seconds to 60 seconds, and T joints from 88 seconds to 81 seconds. The quality of the welding results is visually better, the results of welding defects are smaller and straighter or symmetrical

Tool Wear in GGG50 Cast Iron Milling Environments

In the present study, the impression of manufacturing parameters on cutting tool tip wear in the milling operation of GGG50 cast iron material with carbide coated cutting tool inserts was investigated. Taguchi orthogonal L18 experimental sequence was applied as the experimental design. As processing parameters; cutting speed, coolant and feed rate were chosen. In the test results, the amount of wear on the cutting tool tips was examined. Optimum processing multiparameters were determined by the Taguchi. Analysis of variance (ANOVA) was used to analyses the effect of input parameters on the cutting tool tip. Consequently, it has been determined that the wear is high in the working environment where the coolant is open and the cutting speed is high. In order to keep the cutting tool tip wear at a minimum level, the most suitable machining parameters are; coolant = closed, cutting speed = 160 mm/min, feed rate = 0.3 mm/rev. It was determined that the tip feed rate had little impression on tool wear.

Improving the efficiency of waste use in China's ferrous metallurgy: Strategic recommendations and optimization of decision-making tools

Improving the efficiency of waste use in China's ferrous metallurgy: Strategic recommendations and optimization of decision-making tools

DEVELOPMENT OF CONSTRUCTIVE DESIGN OF PICKLING UNITS FOR OPERATION IN HIGHLY AGGRESSIVE HOT SULPHURIC ACID SOLUTIONS

Problem statement. Technological process of metallurgical, pipe-rolling, chemical and other enterprises includes chemical treatment of metal products by pickling in hot (60–80 °C) sulphuric acid solutions with a concentration of 20–22 %. This treatment method is conducted in the pickling departments of enterprises in special containers (pickling units). Pickling solution of the specified concentration and temperature is a highly aggressive environment for all building structures made of traditional materials. Existing pickling units for chemical treatment of metal products do not ensure reliability and durability and are destroyed after 1-2 years of operation. Therefore, ferrous metallurgy enterprises that have pickling departments for chemical treatment of metal structures are classified as enterprises with a highly aggressive environment and their design should be developed with these conditions under consideration. The purpose of the work: Searching for and implementing mechanisms to improve the resistance of polymer concrete in aggressive environments in production. The object of research – is furan resins modified polymer concrete. The subject of the research – investigation of the particularities and improvement of constructive design for pickling baths made of materials based on polymer concrete in an aggressive environment and its implementation in production. Main part. Development of constructive design for technological pickling units made of structural corrosion-resistant material (furan resins modified polymer concrete). Conclusions. Pickling of metal products at ferrous metallurgy enterprises is conducted in highly aggressive hot sulphuric acid solutions of 20–25 % concentration at a temperature of 60–80 °C. Under the conditions of constant exposure to highly aggressive hot sulphuric acid solutions, even protection with chemically resistant materials does not ensure the required reliability and durability. To manufacture such structures, a new structural material is needed that combines chemical resistance with strength and durability. This material is a structurally chemical-resistant polymer concrete based on thermoset furan resins, which have high strength and universal chemical resistance, allowing us to solve the problem of reliability and durability of technological units for chemical treatment of metal structures at ferrous and non-ferrous metallurgy enterprises in a fundamentally new way. New constructive design for pickling units made of reinforced polymer concrete was developed in conjunction with shock-absorbing bars and an improved ventilation system, consisting of individual elements of full factory readiness weighing no more than 5 tonnes, which allows them to be transported and installed in operating pickling workshops using existing mechanisms.

Using Iron Stable Isotopes to Quantify the Origins of the Cryoconite Iron Materials in Western China and Exploring Controlling Factors

AbstractIron (Fe) has profound impacts on Earth's ecosystem and global biogeochemical cycles. Fe deposited onto glacier surfaces reduces snow and ice albedo, thereby accelerating glacier melting, and supplying downstream ecosystems with dissolved Fe. However, the origins of atmospheric Fe deposition in glacier regions of western China remain unclear. This study presents novel insights into Fe isotopic composition (refer to δ56Fe) and origins, gained from geochemical analysis of large‐scale cryoconite samples collected from glaciers in western China, which encompass the Tibetan Plateau (TP) and the Tianshan Mountains. Results showed that cryoconite δ56Fe ranged from −1.06 ± 0.07‰ to 0.33 ± 0.04‰, regardless of their concentration. Moreover, anomalous δ56Fe values deviating significantly from the upper continental crust values (with an average of 0.09‰) were detected, indicating a significant impact of anthropogenic Fe materials on the investigated glaciers. This impact was particularly prominent in the margin regions of the TP and its surroundings, but was less apparent in the interior and southern of the plateau. Using MixSIAR isotope mixing model, we determined that coal combustion and other anthropogenic combustion sources (such as liquid fuel combustion and steel smelting) contributed to cryoconite Fe in the range of 6.9%–43.1% and 0.8%–23.4%, respectively. Among these, coal combustion was the predominant anthropogenic source of cryoconite Fe in western China's glaciers. Compared with other sink areas in the Northern Hemisphere, glaciers in western China are obviously affected by anthropogenically sourced Fe. This study has significant implications for understanding glacier‐fed downstream ecosystems and the regional biogeochemical cycle.

Study on micron Zero-valent Iron (mZVI) material for adsorption and removal of antimony (V)

In this study, micron Zero-valent Iron (mZVI), an affordable and well-dispersible reducing agent, was investigated for its potential application in removing Sb(V) from wastewater. Since Sb(V) primarily exists as Sb(OH)6- in aqueous solutions, the lower the pH, the more effective mZVI is in removing Sb(V). At a pH level of 3, mZVI (1.0 g/L) was able to remove more than 99 % of Sb(V) (20 mg/L) from the wastewater. The study also compared the influence of cations and anions on mZVI and found that anions had a greater impact on the material's performance. The paper further examined the impact of different heavy metal ions on mZVI and determined that the adsorption capacity of mZVI towards these ions follows the order of their reducing ability. Summarizing the removal mechanism of Sb(V) by mZVI, it was found that both adsorption and redox reactions played crucial roles and Sb(V) is ultimately removed from water through coprecipitation by combining with Fe-O on the mZVI surface. Theoretically, the maximum adsorption capacity of the mZVI material used in this study could reach 21.60 mg/g for Sb(V). This makes mZVI a promising environmental adsorption material and a potential solution for treating water pollution caused by antimony mining.

Contribution to the Fracture Mechanics Characterization of Repair Welding of Thick-Walled Ductile Cast Iron Components

AbstractFor the spheroidal graphite cast iron materials, also known as ductile cast iron (DCI), EN-GJS-400-18-LT and EN-GJS-450-18, different welding procedures were examined for potential repair welding. A repair weld was performed on thick cast iron plates using the optimum procedure in each case. The weld was evaluated for all areas of the welded joint (weld metal, fusion line/heat-affected zone and base metal). In addition to the metallographic microstructural analysis, the characterization of the repair weld was carried out by means of hardness distribution measurements, static tensile testing and notched bar impact testing as well as fracture mechanics investigations under static and under cyclic loading in a wide load ratio range. On this basis, a generalized description of cyclic crack growth could be made according to the NASGRO® MODEL. NASGRO® is a fracture mechanics and fatigue crack growth software. In accordance with the possible operating conditions of repair-welded, thick-walled components, the static and impact tests were performed in the temperature range down to $$-$$ - 40 $${}^{\circ }\text {C}$$ ∘ C .

Modernization of Coke Production at Magnitogorsk Iron and Steel Works (MMK)

Modernization of Coke Production at Magnitogorsk Iron and Steel Works (MMK)

익산지역 마한문화의 성립과 변천

It is generally believed that Mahan was founded before the 2nd century BC. According to historical records, Mahan began with King Jun's migration and settlement in the Iksan area. Since there are not many cases that have been investigated in relation to the residential areas with living remains, few facts of them are known accurately. The tombs constructed include wooden coffin tombs with stone mound, pit tombs, and jar coffin tombs. Out of them, however, wooden coffin tombs with stone mound and pit tombs from an early period are sporadically identified, and the mainly excavated relics are bronze ware. Following the southward transfer of King Jun, a large group of tombs were constructed as in Madong, and the relics excavated are featuring both bronze and iron ware. In light of this, it can be said that the Mahan society in the Iksan region during the establishment period developed by actively accepting advanced civilization. Around the 1st century, the Mahan society in the Iksan region faced a period of stagnation, and villages began to be built in full swing after the 2nd century AD, reaching a peak in the 3rd to 4th centuries AD. Large-scale settlements appeared in places like Sadeok and Jangshin and small- and medium-sized villages were formed and organically connected to each other around the large-scale settlements in the center. As for tombs, mounded tombs with an encircling ditch began to be built in earnest, and it can be seen as the developing period of Mahan culture.. The Mahan culture in the Iksan area sustained even after Baekje territorialization. Such dwellings as four-pillar and non-four-pillar types of Mahan culture continued and, in some dwellings, fire pits made of plate stone and utensils which can be seen as Baekje elements appear and Baekje pottery is found in the sites of dwellings. Furthermore, dwelling sites with pillars used for walls related to the center of Baekje made an entrance. Tombs of the Mahan tradition also continued to be built even after Baekje territorialization. However, the stone chamber or stone-lined tomb related to the center of Baekje were employed for burial body and the grave goods changed to Baekje pottery, while Baekje pottery was excavated within the burial mound. In the areas of Ipjeom-ri and Ungpo-ri, the lower reaches of the Geumgang River, stone- built tombs of Baekje style were built in the mid-5th century, an evidence confirming that Baekje first took control of the lower Geumgang River, an important waterway transportation route and gateway. After the Gwangam-ri area in the middle of the Mangyeong River basin first became Baekje territory, Baekje central culture seemed to have entered the surrounding areas, too.

Enhanced photoacoustic signal processing using empirical mode decomposition and machine learning

ABSTRACT In this study, we propose a robust photoacoustic (PA) signal processing framework for a material independent defect detection using empirical mode decomposition (EMD) and machine learning algorithms. First, a database of the PA signals with 960 samples has been obtained from aluminium, iron, plastic and wood materials using a laser, microphone and data acquisition board-based PA apparatus. Second, the EMD based time and time-frequency domain techniques are proposed to extract robust cross-material feature space focusing on laser induced acoustic signal, and the decomposed intrinsic mode (IMF) with 14 extracted features are performed on totally 960 samples PA signals to evaluate k-nearest neighbour (k-NN), decision tree (DT) and support vector machine (SVM) classifiers. Inter- material and cross-material evaluations are performed, and the accuracy rates up to 100% for SVM and 97.77% for k-NN are yielded.

Bending of Sheet Metal (st37) Using 90 Degree to Estimate Blank Dimensions

Several factors must be considered whendesigning parts that are being made by bending. Theprimary factor is minimum radius and angle of bending thatcan be bent successfully without metal cracking. Lowcarbon steel metal (st37), manufactured by Libyan Iron andsteel Company, was used in this study. Various bendingprocesses by Vee die for different radii and calculatethickness were conducted and bending zones were tested tofind the mean radius and calculate the bending allowance.These calculations depend upon the inner bend radius andthickness of the sheet metal. The thickness was reduced andthe neutral axis were moved up in the direction ofcompression side. Form the values of reduction in thicknessand different radii of bending a chart was drawn. Anotherchart was drawn to minimums the process of trial and errorfor estimating the blank length of the bending sheet metal.Form these charts, the initial blank sizes can be determined,so that products can bend without loss and crack in thematerial. As a result time and material can be saved. Theresults of the present study can have practical applicationsfor this material (st37) which is in common use by theLibyan industry.

Study of cast iron pots and slags from Salovka I settlement

The article presents the geometric size and shapes of cast-iron pots which were found at the Salovka I settlement in the Upper Sura region. Also the paper reflects the results of studies of one of the fragments of a cast-iron pots, repair plate and slag from the settlement. Slag samples were studied by chemical analysis using methods for the determination the iron content in ores, concentrates and agglomerates. The repair plate and a fragment of the cast iron pot were analyzed using an electron beam spectrograph. In results a noticeable amount of phosphorus was found in the studied samples. This is due to the use of marsh, lake and meadow ores as raw materials for the local ferrous metallurgy. In order to form a statistical database on iron casting and blacksmithing in the Upper Sura basin and other areas, it is necessary to conduct further analytical research.

Phase transformation of schwertmannite in paddy soil under different water management regimes and its impact on the migration of arsenic in soil

Schwertmannite (Sch) holds a great promise as an iron material for remediating Arsenic (As)-contaminated paddy soils, due to its extremely high immobilization capacities for both arsenate [As(V)] and arsenite [As(III)]. However, there is still limited knowledge on the mineral phase transformation of this metastable iron-oxyhydroxysulfate mineral in paddy soils, particularly under different water management regimes including aerobic, intermittent flooding, and continuous flooding, and how its phase transformation impacts the migration of As in paddy soils. In this study, a membrane coated with schwertmannite was first developed to directly reflect the phase transformation of bulk schwertmannite applied to paddy soils. A soil incubation experiment was then conducted to investigate the mineral phase transformation of schwertmannite in paddy soils under different water management regimes and its impact on the migration of As in paddy soil. Our findings revealed that schwertmannite can persist in the paddy soil for 90 days in the aerobic group, whereas in the continuous flooding and intermittent flooding groups, schwertmannite transformed into goethite, with the degree or rate of mineral phase transformation being 5% Sch >1% Sch > control. These results indicated that water management practices and the amount of schwertmannite applied were the primary factors determining the occurrence and degree of mineral transformation of schwertmannite in paddy soil. Moreover, despite undergoing phase transformation, schwertmannite still significantly reduced the porewater As (As(III) and As(V)), and facilitated the transfer of non-specifically adsorbed As (F1) and specifically adsorbed As (F2) to amorphous iron oxide-bound As (F3), effectively reducing the bioavailability of soil As. These findings contribute to a better understanding of the mineralogical transformation of schwertmannite in paddy soils and the impact of mineral phase transformation on the retention of As in soil, which carry important implications for the application of schwertmannite in remediating As-contaminated paddy soils.