Increasing the mechanical properties of structural cast iron for machine-building parts by combined Mn – Al alloying

Popov, Stanislav; Frolova, Liliia; Rebrov, Oleksii; Naumenko, I. I.; Postupna, Оlenа; Зубко, Владислав Миколайович; Shvets, P. U.

doi:10.21303/2461-4262.2022.002243

Cited by 4 publications

(4 citation statements)

References 25 publications

(26 reference statements)

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“…This forms rational technological modes of processing the cast iron melt outside the furnace [17], which have the potential for optimization. For such optimization, mathematical models of the «composition-properties» type are built [18], choosing as an optimization criterion the one that is the most important from the point of view of operational requirements -for parts of internal combustion engines [19], mixer blades and other mechanical engineering parts [20][21][22].…”

Section: Engineeringmentioning

confidence: 99%

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Demin¹

2023

Eureka: PE

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The object of research is the temperature regime of melting in a cupola. The synthesis of optimal control of such an object is associated with the presence of a problem consisting in the complexity of its mathematical description and the absence of procedures that allow one to obtain optimal control laws. These problems are due to the presence of links with a pure delay, non-additive random drift, and difficulties in controlling the process parameters, in particular, accurately determining the temperature profile along the horizons and the periphery of the working space of the cupola. The proposed conceptual solution for the synthesis of optimal temperature control allows the use of two levels of control: the level controller solves the problem of maintaining the constant height of the idle charge, and the problem of increasing the temperature of cast iron is solved by controlling the air supply to the tuyere box. It is shown that the problem of regulating the upper level of an idle charge can be solved by reducing the model of the regulation process to a typical form, followed by the use of the Pontryagin maximum principle. A procedure for the synthesis of optimal air flow control is proposed, which makes it possible to obtain the temperature regime control law on the basis of experimental industrial studies preceding the synthesis process. This takes into account the time delay between the impact on the object and its reaction, which makes it possible to predict the temperature value one step acharge, equal to the time interval during which the lower surface of the fuel charge reaches the upper surface of the level of the idle charge. A procedure for temperature profile control based on the use of D-optimal plans for selecting sensor installation points is proposed. Due to this, it becomes possible to determine the temperature profile of the cupola according to its horizons and the periphery of the working space of the cupola with maximum accuracy. The proposed synthesis method can be used in iron foundries equipped with cupolas, as it is a tool for studying a real production process, taking into account its specific conditions. This will allow developing or improving control systems for cupola melting, implementing different control modes: manual, automated or automatic

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Section: Engineeringmentioning

confidence: 99%

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Demin¹

2023

Eureka: PE

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“…Thus, issues of the formation of properties, as the final stage of all physical and chemical transformations, require modeling, regardless of the brand of cast iron. In support of this, studies can be cited concerning the smelting of cast iron with flake graphite [5,6], malleable cast iron [7], aluminum cast iron [8,9], special wear-resistant and alloy cast iron [10,11]. All these works are limited to the chemical compositions for which studies were carried out and properties and structure were evaluated.…”

Section: Introductionmentioning

confidence: 99%

The choice of rational adjustment of the chemical composition of iron melted in an electric arc furnace on the basis of technological audit of serial films

Nikolaev

2024

TAPR

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The object of research in the work is cast iron of the SCh20 grade according to GOST 1412-85 (DSTU EN 1561, EN-GJL-200), which is melted in an electric arc furnace. In this work, the parameters of serial smeltings of cast iron used for machine-building castings were determined, which were used to select the content of elements of the chemical composition. The existing problem is that the impossibility of taking into account many factors influencing the formation of the chemical composition of cast iron during smelting leads to deviations of the chemical composition from the requirements regulated by the technical conditions. The main reason for this is the uncontrollability of the chemical composition of the charge materials and the difficulty of accurately determining the soot of the elements during the smelting process. This can lead to the formation of a shortage of cast iron, or to excessive costs for smelting, associated with the need for additional technological operations and the use of additional materials to eliminate detected deviations of the composition from the requirements. The procedure of technological audit of serial smeltings is proposed, the feature of which is a comprehensive assessment of the actual indicators of smelting. They include: mathematical expectations of the content of the elements of the chemical composition, estimates of their dispersions, root mean square deviations, systematic errors, scattering fields and deviations of the lower and upper limits of the content of each element from the lower and upper limits required by the technical conditions. The results of such an audit are the possibility of calculating corrective combinations of charge materials and ferroalloys, which eliminate inaccuracies in the calculation of the charge and the determination of the heat of the elements during the smelting process. As a result of the audit of a sample of 31 serial smelters, it was established that the average content of the elements C, Mn, Si, Cr exceeds the average required by technical conditions. These deviations are: +0.04 % C, +0.06 % Mn, +0.038 % Si, +0.06 % Cr. To compensate for these deviations, the following combination of charge materials and ferroalloys, which are introduced into the melt before delivering the cast iron to the casting area, is proposed: 44 kg of steel scrap +88 kg of recycled iron. The presented study will be useful for machine-building enterprises that have foundries in their structure, where iron is melted for the production of castings.

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“…-gray with lamellar graphite [6][7][8][9]; -aluminum [10,11]; -special wear-resistant [12]. This approach is promising, but requires the use of a minimum number of influencing factors to build an adequate mathematical model.…”

Section: Introductionmentioning

confidence: 99%

Revealing the significance of the influence of vanadium on the mechanical properties of cast iron for castings for machine-building purpose

Frolova

Barsuk²,

Nikolaiev³

2022

TAPR

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The object of study in this work is cast iron with lamellar graphite, modified with two types of modifiers – FeSi75 and FeSi40V7. In this work, the influence of vanadium on the mechanical properties of cast iron used for castings for engineering purposes was determined. The existing problem lies in the fact that ignorance of the influence of the alloying element on the mechanical properties of the alloy does not allow determining its consumption rates during the melting process. This can lead to unnecessary costs for materials for melting and casting, and not be justified in terms of the expected improvement in properties. To determine the effect of vanadium on properties, three indicators of the quality of cast iron are considered: tensile strength, stiffness, and a generalized quality index for mechanical properties. A decision is proposed on the procedure for checking the significance of the influence of vanadium within the considered range of variation V=0.04–0.078 % on these indicators. It has been established that the introduction of vanadium into cast iron as part of the FeSi40V7 modifier leads to a decrease in the tensile strength by 4 %, but to an increase in rigidity by 2 %. A significant influence of vanadium with a probability of 95 % was also established with respect to the generalized quality indicator for mechanical properties – the introduction of vanadium contributes to a drop in this indicator by about 5 %. As a result, it was concluded that the use of vanadium in the composition of FeSi40V7 within the final content in cast iron at the level of 0.04–0.078 % can be expedient only if it is necessary to increase the hardness of cast iron due to the promotion of carbide formation during alloy crystallization. The presented study will be useful for machine-building enterprises that have foundries in their structure, where cast iron is smelted for the manufacture of castings.

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Increasing the mechanical properties of structural cast iron for machine-building parts by combined Mn – Al alloying

Cited by 4 publications

References 25 publications

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

The choice of rational adjustment of the chemical composition of iron melted in an electric arc furnace on the basis of technological audit of serial films

Revealing the significance of the influence of vanadium on the mechanical properties of cast iron for castings for machine-building purpose

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