About the program

Abstract

Targeted scientific and technical program "Development and implementation of technology for the production of complex-alloy steels with a homogeneous structure due to the synergy of effects on the melt."

The purpose of the program: Development of technologyproduction of complex alloy steels with a homogeneous and defect-free structure due to the synergy of external and internal effects on the melt during the primary crystallization process with nanopowder modifiers, inoculators and combined magnetic and vibration treatment to improve the performance properties of castings and subsequent implementation of the technology in production.

Relevance of the program is determined by the following. One of the leading sectors of our country's economy is the mining and metallurgical industry. A significant portion of the equipment used in the mining and metallurgical industry operates in extremely aggressive conditions (wear, high temperatures, corrosive effects, etc.).

In this regard, most equipment is made of complex alloy steels, which determines the high cost. At the same time, the service life of the equipment is usually, on average, no more than two years, after which it is replaced or repaired. This, in turn, leads to downtime, reduced productivity, etc.

In this regard, to increase the reliability and service life of equipment, it is necessary to use materials with improved performance properties. At the same time, the possibilities of increasing the mechanical properties and durability of complex alloy steels by using new alloying elements and/or heat treatment are practically exhausted.

The use of new alloying elements in such steels actually leads to the development of new alloys with subsequent development of technological modes of smelting, production of castings, finishing of parts, etc. In such a case, material and time investments are required in the development of new technology and its implementation in production.

This program proposes to approach the solution of creating parts from complex alloy steels with improved performance properties using a fundamentally new approach that ensures minimal costs for improving the mechanical properties and durability of operation of parts from such steels.

Scientific novelty of the program.The idea is based on the use of simultaneous internal (inoculants, modifier nanopowders) and external (magnetic treatment, mechanical vibrations) effects on the melt during the period of primary crystallization of existing steel grades.

Such an impact will lead to the formation of a homogeneous defect-free structure, which will provide a new level of operational properties. The morphology of grains in the structure will be changed, homogeneity will increase, chemical liquation will be excluded, the content of non-metallic inclusions will decrease, conditions will be created for the formation of new strengthening highly dispersed phases.

The proposed technology for influencing the melt consists of using nanopowders of modifiers and inoculators of various natures and subsequent treatment of the melt with mechanical vibrations and a magnetic field.

It is proposed to use nanosized refractory powders of carbides and oxides of some metals as nanomodifiers, and technogenic waste from foundry and metallurgical production as inoculators. Modifiers will facilitate the refinement of the structure by increasing the rate of formation of crystallization centers, and inoculators will allow regulating the speed and uniformity of the crystallization process.

The fundamental difference of the proposed idea consists in the synergy of the impact on the formation of the ingot structure with the simultaneous use of internal (introduction of inoculators and nanomodifiers) and external (magnetic field, mechanical vibration) impact on the melt during the period of primary crystallization.

The developed technology will not lead to a significant complication of the technological process and will not require large investments for the acquisition of fixed assets (except for the installation for creating a magnetic field). In some cases, it will be possible to exclude or simplify the heat treatment of parts.

Expected result. The developed technology will increase the main quality indicators of steels, such as impact toughness, tensile and compressive strength, wear resistance, and purity of the structure for non-metallic inclusions and gases. The expected increase in these indicators is 15-20%.

It should be noted that the implementation of the developed technology will not lead to a significant increase in the cost of production, since the proposed complex effect on the alloy requires a small amount (up to 1%) of nanomodifiers and inoculators, and the initial investment in the purchase of additional equipment is compensated by an increase in the quality of finished products and an increase in the service life of parts.

Basic approaches to conducting research consist of obtaining information and analyzing it, developing hypotheses about strengthening mechanisms as a result of simultaneous internal and external influences on the alloy and their experimental confirmation.

The solution to the set tasks will be achieved by using modern research methods: X-ray phase analysis, electron microscopy, micro-X-ray spectral analysis, methods for determining mechanical properties, and the use of computer modeling.

In order to confirm the objectivity of the obtained results, it is planned to conduct control studies in the laboratories of the Institute of Metallurgy J. Lamur (University of Lorraine, Nancy, France), Vilnius Gediminas Technical University (Vilnius, Lithuania), and Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia).

The importance of the program. The developed technology is of strategic importance for Kazakhstan, since its use will solve one of the existing problems of the country's ferrous metallurgy - its own production of complex alloy steels. In Kazakhstan, complex alloy steels are currently almost not produced, more than 92% of the total consumed volume of such steels is imported from abroad. The volume that is produced in the country is of fairly low quality due to various reasons.

The use of the developed technology will improve the quality of the produced steel and, in general, reduce the import of complex alloy steels.

Achieving all the objectives set in the Program will have a positive effect on the socio-economic state of the country as a whole, since the developed technology will increase the range of manufactured parts and the number of jobs, and reduce the volume of imports.

The demand for the results of the Program in production is confirmed by the presence of co-financing from one of the leading manufacturers of mining and metallurgical equipment in the Republic of Kazakhstan, TOO KMZ im. Parkhomenko (Karaganda).

Explanatory note

2. General concept of the program.

2.1. Introductory part.

Main idea of the program consists of using simultaneous internal (inoculants, nanomodifiers) and external (magnetic treatment, mechanical vibrations) effects on the melt during the period of primary crystallization of complex-alloy steels.

2.2. Purpose of the program.

Development of technologyproduction of complex alloy steels with a homogeneous and defect-free structure due to the synergy of external and internal effects on the melt during the primary crystallization process with nanopowder modifiers, inoculators and combined magnetic and vibration treatment to improve the performance properties of castings and subsequent implementation of the technology in production.

2.3. Objectives of the program.

1.Monitoring the Kazakhstan market in order to determine the use of complex alloy steels and monitoring global trends, managing the structure and properties and analyzing the conditions for adapting them to the industrial conditions of the Republic of Kazakhstan.

As a result of solving the specified problem:

- the most common grades of alloy steels used in the Republic of Kazakhstan in the production of mining and metallurgical equipment parts will be determined, and problems in their manufacture and operation will be identified;

- based on information analysis, types of nanomodifiers and inoculators were determined.

The criterion for completing this task will be the selection of research objects and research subjects.

2. Definition and implementation of logistics activities in order to effectively implement all technological stages.

The solution to this problem is important for determining the sequence of technology implementation.

The criterion for completing the specified task will be a process flow chart with a link to specific production sites.

3. Mathematical and computer modeling of thermodynamic systems of complex alloy steels.

This task will allow us to describe the phase formation processes that occur during the crystallization of complex alloy steels when exposed to various factors.

The criterion for the successful solution of the set task will be the simulated diagrams of the state of thermodynamic equilibrium of experimental systems and preliminary mathematical dependencies of various technological parameters on the properties of the melt.

4.Development of technology for processing melt after release from the furnace by controlling the structure and properties through the introduction of nano-modifiers and external influence during the crystallization period.

This task has several subtasks, which indicates that this task is the main one:

- selection of types of nanomodifiers and inoculators taking into account available data on modern production;

- development of a hypothesis for improving the properties of a complex alloy using nanomodifiers and magnetic and mechanical treatment;

- conducting basic experiments in laboratory conditions and drawing up an experimental planning matrix;

The criterion for the successful solution of the task will be the preparation of a preliminary technological map with the definition of all technological parameters.

5. Study of the structure and properties of complex alloy steel,hardened according to developed technological regimes in order to adjust the steel processing process.

This task is constant throughout the entire continuation of the Program and is directly related to the previous one.

The criterion for completing this task will be the establishment of relationships between the quantity and nature of nanomodifiers and inoculators, and the parameters of magnetic and mechanical effects on the structure and properties of the objects under study.

6.Testing of the developed technology in industrial conditions and production of a batch of castings in order to determine their durability under operating conditions.

Based on the results of solving this problem, the conditions will be determined and adjustments will be made to the technological modes of using the technology in production based on the results of testing the developed technology.

The criterion for the completeness of the task will be the act of conducting industrial tests and manufacturing prototypes.

7.Development of technological documentation for the further implementation of the developed technology at enterprises in the country specializing in metallurgical and foundry production.

The importance of solving this problem lies in the need to use regulations in production for the implementation of the developed technology, for the promotion of the obtained results through an advertising campaign with subsequent commercialization of the results of the Program.

The criterion for completing the task will be the implementation act and the process flow chart agreed with the relevant production.

8.Conducting an advertising campaign for the developed technology with the aim of expanding the circle of potential consumers, promoting the product on the market and increasing its competitiveness.

The solution to the presented problem will contribute to the popularization of the achieved results, the search for potential partners, which will allow the commercialization of the scientific results of the Program.

The criterion for solving this problem will be the signing of at least 3 letters of intent with production partners.

3) The level of technological readiness of the development at the submission stage is level 5-6 (Experimental developments - pilot production and testing)

At present, laboratory studies have been conducted on the influence of technological modes of ultrasonic and mechanical action on the structure and properties of alloys. Also, separate studies have been conducted on the development of the technology of using inoculators and modifiers when introducing them into the casting directly into the casting mold. It has been proven that the use of external and internal action on the crystallizing melt promotes alignment of the structure throughout the volume of the casting, minimizes chemical liquation, and allows avoiding casting defects. The results of these studies have been published in journals recommended by KOKSNVO.

At the KMZ named after Parkhomenko, TOO, pilot tests were conducted on the use of the obtained technological modes to improve the quality of casting in production conditions. However, these tests were conducted separately for external and internal impact on the structure and properties of castings.

The next step for this complex technology for producing defect-free homogeneous complex-alloy steels is the use of complex simultaneous internal and external influences.

Uthe level of technological readiness of the development upon completion of the program is level 9 (experimental development - production).

After testing and adjusting the modes of complex impact on casting in laboratory and production conditions, a complete set of technological documentation will be developed, and the technology itself will be implemented in production at one specialized enterprise.

Based on the results of previously conducted studies, more than 10 articles were published in journals recommended by the KOKSNVO and in journals included in the Scopus list; 5 patents of the Republic of Kazakhstan and 1 Eurasian patent were received.

Scientific novelty and significance of the program

1) The operating conditions of equipment in the mining and metallurgical sector are severe: high temperature, increased wear, gas corrosion, heavy loads, long service life, etc. Accordingly, increased requirements are imposed on the basic properties (strength, hardness, impact strength) and special properties (wear resistance, heat resistance, etc.) of materials used in the mining and metallurgical sector. Obviously, to ensure such properties, either special alloys or complex alloyed steels are used for manufacturing [1].

However, at present the reserve for increasing properties by using new alloying elements or improving heat treatment is practically exhausted. In addition, in such a case significant material and time investments are required in developing new technology and implementing it in production.

Therefore, one of the modern trends in improving the properties of complex alloy steels is the use of different methods of influence, associated, for example, with nanomodification, mechanical vibration influence, the influence of a magnetic field and ultrasound on the melt or other influences.

It should be noted that one of the main trends in improving the properties of alloy steels is nanomodification [1-12], and the steel obtained after such treatment is considered as a reinforced or composite material of a new generation [4, 7,11]. All of the above studies show that the introduction of nanoparticles of refractory compounds into the alloy steel melt leads to grain refinement, increased hardness and strength. In some cases, the introduction of nanomodifiers leads to an increase in special properties such as wear resistance or heat resistance.

In previously conducted studies [13-15], the authors of the Program showed the results of works on the influence of inoculators and nanomodifiers of various nature on the structural and strength characteristics of alloy steels. These works showed the positive dynamics of the effect of both inoculators and nanomodifiers on the properties of steels. The results previously achieved by the authors of the Program are planned to be used in the development of technology for the production of complex-alloy steels with a homogeneous defect-free structure due to the synergy of external and internal effects on the melt.

Another popular trend in improving the properties of alloy steels is the extra-furnace effect on the melt. Vibration, ultrasonic treatment, and magnetic field effects are considered as such effects [16-25].

In the work [16] the dependence of the alloy properties on the impact of a magnetic field, ultrasound and vibration effects on it during the crystallization process is considered and analyzed. The work notes that, despite the existing discrepancy in the quantitative impact of external factors on the mechanical properties of the alloy, the qualitative effect is determined by an increase in strength characteristics under the influence of a magnetic field, ultrasound and vibration effects.

The paper [17] presents the results of studies of the effect of a magnetic field on the strength characteristics and the conditional yield strength of 35KhM steel. Engine parts obtained both by the traditional method and after exposure to a magnetic field were considered as samples. It is noted that the strength limit increases by 12-15%, and the dislocation density increases. An increase in the homogeneity of the structure determines a decrease in microdefects, and, as a result, improves the mechanical properties of the entire alloy.

Also, improvement of alloy properties due to the effect of a magnetic field is shown in works [18-20]. In all these sources, the effect of a magnetic field on different objects of research (aluminum alloys, different grades of steel) was considered, and it was shown that under the influence of a magnetic field, positive dynamics of the rate of formation of nuclei during the first stage of primary crystallization, a decrease in grain sizes and dislocation density are observed. In this case, the level of influence of a magnetic field is determined by its characteristics. The presence of a "memory effect" of magnetic action, which lasts about 5-15 minutes, is also noted.

The work [21] shows the positive influence of external action on the microstructure and properties of copper alloy composites. An increase in tensile strength, yield strength and relative elongation is noted.

It should be noted that the previously performed literary analysis of the state of the art in this area clearly shows the feasibility of the impact of nanomodification on steel with the simultaneous use of external mechanical or magnetic influences.

However, in all sources, nanomodification was carried out directly in the furnace, and the effect of a magnetic field or mechanical vibrations was considered as a subsequent operation of steel processing.

A distinctive featureThe proposed project is the simultaneous use of internal (introduction of inoculators and nanomodifiers of a certain composition into the melt) and external (use of a magnetic field and mechanical vibration) effects on the melt during the primary crystallization period. It is proposed to carry out nanomodification directly in the ladle (mold) with subsequent processing by vibration and a magnetic field. In such a complex combination of effects, the maximum synergistic degree of positive influence of all factors of influence will be achieved to improve the structure, reduce liquation, gas saturation, improve the main mechanical and special properties.

The correct choice of nanomodifier (origin, conditions of introduction into the melt, fractional composition) will make it possible to improve both the strength and special properties of alloy steel.

It should be noted that the use of a nanomodifier of the required nature will allow imparting completely new properties to already known steel grades, since the introduction of nanomodifiers actually leads to the creation of a material of a new nature, such as reinforced or composite, without significant changes in the chemical composition. In this case, nanoparticles or new phases of introduction associated with the introduction of nanoadditives play the role of a "framework" in the existing matrix. It should be emphasized that the term "nanomodification" in this case has a broader meaning, since it implies not only a change in structure, but also the possible formation of new phases, in the case, for example, of using nanoparticles of refractory metals.

For our country, the proposed Program is fundamentally new, since there are practically no studies devoted to the complex effect on the melt of alloyed steels. It should be emphasized that this issue has strategic importance, since it will be possible to significantly increase the quality of the produced complex alloyed steels, increase the durability of parts in practice as a result of increasing the characteristics of the main and special properties. The use of such a complex effect on steel will not require significant investments, existing fixed assets will be used for the technology. The technology proposed for development will be successfully adapted to existing production process chains, and the project will pay off in a short time.

2) The implementation of the program is aimed at solving the main tasksConceptsAnddevelopment of the manufacturing industry for 2023-2029.:"…- Advanced creation of specialized factors of production in spatial “growth points”;

- Creation of new large capital-intensive and knowledge-intensive industries;

- In the mining engineering sector, it is necessary to create foundries (shops) for the production of blanks for the engineering industry;

- In the railway engineering sector, it is necessary to master foundry production, forging and stamping for enterprises…”.

In addition, the Program is aimed at solving the tasks of the Strategy "Kazakhstan - 2050": "By 2050, Kazakhstan must completely update its production assets in accordance with the latest technological standards. In the most competitive industries, we need to actively develop strategies for the formation of new market niches for domestic producers" and the Strategic Development Plan of the Republic of Kazakhstan until 2025 under the priority "Creating the Foundations for a New Economy".

The mining and metallurgy sector, as well as the manufacturing industry in general, is one of the main sectors for the economy of our country. It should be emphasized that a significant portion of the products manufactured in this sector do not have high added value. For example, in Kazakhstan, according to various estimates, only 5-7% of alloy steel is produced from the volume consumed as a whole, and the missing amount of steel is imported into the country. This situation indicates the direct dependence of our country on supplies from abroad and causes an increase in the cost of manufactured products based on alloy steels.

At the same time, the range of alloy steel grades manufactured in Kazakhstan includes few quality steels and the choice of such steels is generally insignificant. This, in turn, leads to a limited choice in the manufacture of our own replacement parts, therefore, imports are even more significant in this segment.

At the same time, our country has great potential for manufacturing its own alloy steels in a significant range. The implementation of the proposed Program will contribute to the solution of these strategically important tasks.

The development of the proposed technology and its further implementation in production will improve the quality of alloy steels manufactured in Kazakhstan and expand the range of domestically produced replacement parts for equipment in the mining and metallurgical sector.

New knowledge will contribute to the development of the national school of metal science and physics of metals, which will enable domestic metallurgical science to reach a fundamentally new level.

3)A significant part of the research conducted on the development of the country's metallurgical industry is related to increasing the efficiency of metal extraction from ores of various deposits and their enrichment. The main result of these studies is the technological modes of obtaining metal concentrates or ferroalloys, which make up about 91% of metallurgical exports.

At the same time, alloy steels, rolled products, pipes and other products with high added value are imported into the country.

The production of alloy steels in Kazakhstan is poorly developed, mainly due to the lack of basic means for the production of such steels. Such a metallurgical giant in our country as JSC "Qarmet" does not have electric arc furnaces, without which it is problematic to produce alloy steels. Other enterprises focused on the production of steels have insignificant production capacities, which do not allow the production of a wide range of steels with high quality.

All this determines the current situation, when Kazakhstan largely depends on imported alloy steels. The implementation and use of the proposed technology in production will make it possible to qualitatively improve complex alloy steels at minimal costs. At the same time, the range of manufactured parts from complex alloy steels will be expanded and, as a result, dependence on imports will be reduced.

An example is the current situation with ground pumps, the demand for which in the mining and metallurgical sector is quite significant. At present, parts for ground pumps are supplied from abroad, since domestic production cannot establish their production in the absence of high-quality alloy steels. The use of a well-established technology of complex processing to obtain high-quality complex alloy steels will make it possible to ensure the release of such products.

4) There are no analogues of this technology in the Republic of Kazakhstan, since there are practically no studies in this area. At the same time, in world practice, the use of nanomodifiers in combination with treatment with external factors in order to improve the quality of alloy steels is one of the trends. However, it should be noted that in the studies currently being conducted, such methods of influencing steel during the primary crystallization period are considered as separate technologies. Information on the simultaneous use of such effects, and descriptions of the technological operations themselves were not found in open access publications.

The implementation and use of the proposed technology in production will make it possible to qualitatively improve complex alloy steels at minimal cost. The mechanical properties of such steels will increase by 25-30%, which will contribute to the competitiveness of Kazakhstani products in this sector of the economy and, over time, will make it possible to replace similar products both on the domestic market and will allow products to enter the international level.

5) There are currently no analogues of the technology being developed. The fundamental difference of the proposed idea is the simultaneous use of internal (introduction of inoculators and nanomodifiers of a certain composition into the melt) and external (use of a magnetic field and mechanical vibration) effects on the melt during the period of primary crystallization.

The developed technology of simultaneous external and internal impact on the alloy will not lead to a significant increase in the production area, will not require large investments for the acquisition of fixed assets (except for the installation for creating a magnetic field). At the same time, in some cases it will be possible to exclude or simplify the heat treatment of parts.

The use of targeted nanomodifiers will make it possible to increase both the quality of the ingot structure and the mechanical and special properties of complex alloy steels.

6) The final product of the Program implementation is the technology for the production of complex-alloy steels with a homogeneous defect-free structure due to the synergy of external and internal influences on the melt.

There are no analogues of the technology proposed for development; experimental samples will have mechanical and operational properties 25-30% higher than those currently used in practice.

It should also be emphasized that, according to preliminary estimates, the cost of castings and the alloy as a whole will increase by no more than 4-6% due to the small amount of nanomodifiers used.

If a potential manufacturer has the basic means to carry out magnetic or mechanical influence on the crystallizing melt, then the cost of production will remain practically unchanged.

7) The applicants have experience in conducting research in the proposed area. The authors have previously studied the effects of nanomodification on the structure and properties of alloys, and the results of the studies have been published in the open press.

The solved research tasks are directly related to the proposed Program, since they provide an opportunity to apply previously obtained knowledge in determining and conducting subsequent experiments. However, in early studies, the applicants did not address the issues of magnetic impact on melts and used a limited number of nanomodifiers.