Preliminary Heat Treatment Research Articles

Improving a technique for producing a polycomponent semi-finished product with high degree of readiness for 3-D printing of functional food

The object of this study is the process of producing polycomponent semi-finished products of a high degree of readiness using a model structure of functional equipment, in particular, based on apple, Jerusalem artichoke, table beet, and sea buckthorn. A feature of the improved technique is the implementation of preliminary heat treatment with hot steam of raw materials: apple – 1.0...2.0 min, Jerusalem artichoke – 3...6 min, and table beet – 6...12 min, respectively. Sea buckthorn was not processed, only technological rinsing was used. Grinding of raw materials was carried out on a double grinding machine (apple, Jerusalem artichoke, and table beet – 0.2...0.5 10-3 m, and sea buckthorn – 0.5...1 mm). The combined production of polycomponent semi-finished products of a high degree of readiness (pastes/fractional powder) was implemented using a model structure of functional equipment. The boiling process in a rotary-film evaporator was carried out at a temperature of 55 °C for 65 seconds to a dry matter content of 25 %. Drying of the cooked multicomponent mass was carried out in a single-drum cylindrical IR dryer at a temperature of 50 °C to a final moisture content of 3...6 % and fractional grinding (0.3...0.6 mm). The rheological properties of the paste-like multicomponent semi-finished product were determined by the change in dynamic viscosity for composition 2, which is 485 Pa∙s, and in the control sample of applesauce, this indicator is 50 Pa∙s. When boiling in a rotary-film evaporator at a temperature of 55 °C to a content of 30 % of dry substances, there is an increase in the strength of dynamic viscosity by 3.2 times (600 Pa∙s), and in the control (apple paste) this indicator is 178 Pa∙s with a dry matter content of 25 %

Modeling of Tensile Stress Distribution Considering Anisotropy of Mechanical Properties of Thin-Walled AlSi10Mg Samples Obtained by Selective Laser Melting

The work that is being presented demonstrates that there is a critical point at which the engineering stress–strain diagram’s elastic–plastic region transitions to yield and fracture stresses. This transition is demonstrated using thin-walled specimens made using selective laser melting technology from high-strength aluminum alloys (AlSi10Mg) that have undergone preliminary heat treatment. It was discovered that the strain-hardening coefficient, which was determined in the section from yield strength to fracture strength, and the critical point have a highly statistically significant association (0.83 by Spearman and 0.93 by Pearson). It was possible to derive a regression equation that connected the strain-hardening coefficient with the crucial transition point. The type of stress distribution in the elastic–plastic region changes (the Weibull distribution changes to a normal distribution) as the plasticity of the thin-walled samples increases. Additionally, the contribution of the probability density of the stress distribution described by the Cauchy distribution increases in a mode near the point at which the probability density of the fracture increases.

Development of a technological solution aimed at improving the consumer properties of a new fish culinary product enriched with chondroitin sulfate of thorny skate

The paper presents the results of developing a fish culinary product (thorny skate meat mixed with Atlantic cod meat, baked with potatoes and mushrooms in a cream sauce) enriched with chondroitin sulfate contained in the meat and cartilage of the wings of thorny skate. Atlantic cod, more familiar to the Russian consumer and successfully complementing the skate's meat with amino acid composition, has been chosen as an additional fish raw material. Thorny skate belongs to the underutilized fishing facilities of the Northern Basin. The meat of its wings contains up to 1.5 % urea, which worsens its organoleptic properties. To solve this problem, it was previously proposed to use short-term preliminary heat treatment (PHT) of skate's wings by blanching them in water at a temperature from 93 to 96 °C for 1–3 minutes, which guarantees a fourfold decrease in the mass fraction of urea in the meat, relative to the initial content, below the organoleptic perception of the consumer. PHT also facilitates the cutting of the skate's meat. The formulation and technology of a combined fish culinary product is proposed, packaged and completely ready for consumer's use. To prolong the shelf life up to 120 days, it is proposed to subject the product to shock freezing with subsequent storage at a temperature no higher than minus 18 °C. To solve the problem of delamination of cream sauce during storage and to improve the consumer properties of the product, an experimentally based technological solution is proposed – the introduction of oat flour in the composition of the sauce formulation as a thickener and structure-forming agent in an amount of 3.5 % per total mass of sauce.

Energy features of friction thermomechanical handling (FTMH) of steel products and the effect on the state of their surface structure

Abstract. Problem. The article deals with the influence of energy and power characteristics of frictional thermomechanical handling of steel products (FTMH) on the state of their surface. Goal. The goal of this work is to study the relationship between the energy and power parameters of steel FTMР and the strengthening result. Methodology. To achieve this goal, the following tasks were solved: fabrication of samples from 65G steel, preliminary hardening heat treatment of samples, hardening of the working surface of samples using FTMO, measurement of the components of the cutting force arising from FTMO using a dynamometer, analysis of the microstructure and microhardness of each sample, comparison of the microstructure, microhardness, and depth of hardening of the experimental samples, conclusions regarding the relationship between the effectiveness of hardening of samples during processing and the energy and power parameters of FTMH. Results. Changes in the structures and properties of samples made of steel, which is used for products requiring a hard and wearresistant surface under the influence of processing to form surfaces with altered properties, are shown. Originality. Measurements of the machining process at FTMH using a dynamometer were carried out and the circumferential (circular) cutting (machining) force was calculated, which made it possible to construct graphical dependencies that allow characterizing the surface hardening taking into account the thickness of the disk. It is shown that the microhardness of the surface of the prototypes was increased to 1300 kg/mm2, which is equivalent to 13000 MPa. Practical value. Recommendations on the optimal thickness of the hardening disk have been made, taking into account the results obtained. The research results can be used in production and research.

(Digital Presentation) The Effects of Heat Treatment on Electroreduction of Tungsten (VI) Oxide

According to the classic scheme of the FFC Cambridge process, oxides of refractory metals are reduced in the solid state. Before electrolysis, oxides are shaped into cylindrical preforms and annealed at high-temperatures (~1000 °С). Therefore, the purpose of this study is to establish the effect of heat treatment of the initial sample of tungsten trioxide on its electrochemical reduction on a solid cathode in a CaCl2–NaCl melt.There are two types of tablets (preforms) were used for research: non-sintered (only compressed) WO3 and annealed at a temperature of 1000 °C. The surface of a pelletized tungsten trioxide sample without sintering is characterized by a uniform distribution of particles, shown in the SEM image (Fig. a). The particles agglomeration is characteristic for the sample WO3 after heat treatment (1000 °С) (Fig. b), which leads to a decrease in the area and an increase in the size of the voids. The unsintered sample has a larger surface area between the particles due to their dispersed state, which facilitates the penetration of the melt compared to the annealed sample.Electrochemical reduction of pressed WO3 samples (d=0.8 cm, h=0.15±0.20 cm, m=0.45–0.50 g) was carried out under galvanostatic conditions (800 °С) with using steel as the cathode and graphite as the anode. It was established that preliminary heat treatment of WO3 does not contribute to its electrochemical reduction. After applying 1.20 A·h of electricity, the porous granules of unsintered WO3 were completely transformed into metallic tungsten (W), which is shown in Fig. c, line 1. However, sintered samples after electrolysis (quantity of electricity is 1.42 A·h) reduced only partially: W – 74.1%; CaWO4 – 25.9% (Fig. c, line. 2).The results show that the reduction occurs more intensively in samples with more micropores, through which mass transfer occurs at the phase interface: tungsten compound to be reduced molten electrolyte mixture. That is why in the unsintered WO3 sample, the electrochemical reduction is faster. It can be assumed that the degree of reduction of WO3 on a solid electrode in CaCl2–NaCl also depends on its crystal structure. The annealed sample (tetragonal structure) is less susceptible to electrochemical reduction compared to the unannealed sample of tungsten trioxide (monoclinic structure). This is due to the fact that tetragonal WO3 (above 740 °C) is resistant to chemical attack, a poor conductor of electricity and has a low surface area. Monoclinic WO3 (from 17 to 330 °C) is more reactive, a better conductor of electricity and has a higher surface area. Figure 1

Использование криогенного охлаждения при волочении нержавеющей проволоки

In the manufacture of wire with high operational and mechanical properties, the use of high total degrees of compression is irrational, since cold plastic deformation reduces the diameter of the wire, and with hot deformation the initial diameter of the wire has its limitations. Therefore, wire processing by thermomechanical method has a huge potential to reduce costs and improve product quality. The article develops a technology of thermomechanical processing of stainless wire, which consists in preliminary heat treatment to obtain an austenitic structure and traditional drawing followed by cryogenic cooling. As a result of such processing, an ultrafine-grained structure consisting of a mixture of austenite and α – martensite and high strength and plastic properties were obtained. When drawing using cryogenic cooling, a structure with an average grain size of 1 microns was obtained, and a microstructure of 2 microns was obtained at ambient temperature.

STRENGTHENING OF THE SURFACE BY FRICTION

The study is devoted to the application of the method of surface hardening by friction Object of study - the process of surface hardening by friction.Subject of study - samples of 65G steel the method allows achieving high values of hardness, strength and wear resistance of materials in a short time and at much lower cost compared to other processing methods. The aim and objectives of the study are to investigate the nature of surface hardening of steel samples by friction. To achieve this goal, the following tasks are envisaged: manufacturing samples from 65G steel in the form of plates, preliminary heat treatment of samples for their maximum thermal hardening, hardening of the surface of samples by friction, analysis of the microstructure and microhardness of each sample, comparison of the microstructure, microhardness and depth of hardening of these samples, conclusions on the influence of processing factors on the hardening result. Based on the experimental data obtained, we constructed graphs of microhardness changes in the cross-section of the samples and studied the microstructures. It can be seen that after friction treatment, a layer with a modified structure is formed in the surface of the samples. The microhardness of the surface is significantly higher (approximately 2 times) than the microhardness of the main part in the samples. Metallographic analysis has shown that the layer formed in the samples has a martensitic structure characterized by a higher degree of dispersion and microhardness compared to the martensitic structure obtained during the previous heat treatment. Changes in the microstructure and microhardness of the samples that were surface hardened using different processing modes were compared. Certain differences in the characteristics of their hardened «white» layers were found. It is also shown that the hardened «white» layer is located along the entire length of the surface in the samples and is continuous and homogeneous.

COMPUTER SIMULATION OF PRELIMINARY HEAT TREATMENT AND RADIAL-SHEAR ROLLING OF BRASS

This paper presents the results of computer modeling of preliminary heat treatment and radial-shear rolling of L63 brass in the Deform program by cellular automata method. Quenching and annealing were simulated as pre-heat treatment modes. Radial-shear rolling consisted of three passes with a compression of 3 mm per pass. The variable parameters were the roll rotation speed (40 rpm, 70 rpm and 100 rpm) and the workpiece heating temperature before rolling (500°C and 700°C). It was found that the most effective mode of preliminary heat treatment of L63 brass is annealing at a temperature of 500°C. The most rational value of the heating temperature of the workpiece before rolling is 500°C, since in this case, at all selected speeds the recrystallization process does not start, which contributes to intensive grain grinding. An increase of roll rotation speed causes additional deformation heating, which contributes to recrystallization and a decrease of grain grinding intensity.

Development of technology for obtaining juice from persimmon fruit (Diospyros kaki L.)

Organizing proper and environmentally friendly nutrition is one of the most pressing problems. Widespread persimmon fruits are of great technological importance as raw materials for the production of concentrated juice, used as a natural sweetener. The object of this study is the processes of obtaining juices from persimmon fruits. Quality indicators were studied in juices prepared by preliminary heat treatment and the use of an enzyme preparation. The juice yield from the Khachia variety was 93.9 %, and from the Hiakume variety – 93.8 %. To prepare concentrated juice, persimmon juice was used, prepared by preliminary heat treatment, and using 0.1–0.2 % enzyme preparation. A scheme for preparing concentrated juice has been developed, which is recommended for use as an environmentally friendly sweetener in food production. The concentrate contained 7.25 µg/100 g of iodine. The prepared concentrate is rich in nutritional components necessary for human life, as well as sugars, phenolic compounds with antioxidant and antimicrobial properties, as well as vitamin C. Nutritional components perform a wide range of functions in the optimal functioning of the immune system and play an important role in metabolic processes. The use of persimmon concentrate in the preparation of various food products increases the bioavailability of many minerals. Therefore, to ensure the nutritional value of the finished product and increase long-term quality storage, it is recommended to use concentrated persimmon juice as a sugar substitute

Heat-acid treatment of georgian and kazakhstani natural heulandite-chabazites

The article considers the processes leading to a change in the structure and properties as a result of thermal treatment followed by acid treatment of natural zeolites from the Rkoni plot of the Tedzami deposit, Georgia, containing up to 80% of heulandite and 10% of chabazite, and from the Chankanay deposit, Kazakhstan, containing up to 70% of heulandite-chabazite mixture, selected for the creation of new bactericidal zeolite filter materials for purification and desinfection of water from various sources. The influence of preliminary heat treatment of the studied natural zeolites on weight loss, the processes of dealumination and decationization during subsequent acid treatment, and the adsorption properties of the final products is described. It has been shown that mass loss is minimal for amorphized samples, dealumination and the participation of sodium ions in the decationization process slow down significantly, and the adsorption capacity for water and benzene sharply decreases with increasing calcination temperature; all these effects are clearly pronounced for heulandite-containing Rkoni tuff, and for the more acid-resistant Chankanay zeolite they are manifested to a lesser extent.

Effects of laser pretreatment on the formation of nanostructured carbon on the surface of chlorinated polyvinyl chloride under high-power ion beam irradiation

The features of formation of surface morphology of chlorinated polyvinyl chloride (pure and with the addition of the catalyst - ferrocene) under the influence of a high-power ion beam of nanosecond duration after the preliminary pulsed laser treatment of the polymer surface have been investigated. It was found that the morphology of the irradiated surface of chlorinated polyvinyl chloride after pulsed laser surface pretreatment differs significantly from the morphology of the irradiated surface of chlorinated polyvinyl chloride after a preliminary stationary heat treatment. For pure chlorinated polyvinyl chloride, pulsed laser pretreatment with increasing power leads to an increase in the porosity of the surface layer after high-power ion beam irradiation, whereas different surface morphologies, including fibers (including polymer fibers) of different diameters, can be obtained for the pre-stationary post-irradiation thermal treatment of this polymer. Pre-stationary thermal pretreatment of chlorinated polyvinyl chloride with the addition of ferrocene (Fe(C5H5)2) leads to a decrease in the diameter of formed carbon nanofibers (with an increase in the treatment temperature). During the pulsed laser pretreatment, an increase in the porosity of the treated layer and a slight increase in the proportion of nanofibers of larger diameter are observed. To explain the obtained differences for pulsed laser and stationary thermal pretreatment, the effect of polymer heating rate on the features of chlorinated polyvinyl chloride decomposition was analyzed.

Effect of Preliminary Heat Treatment on the Formation of Structure and Residual Stresses in the AMg6 Alloy at Laser Shock Peening Without Coating

Effect of Preliminary Heat Treatment on the Formation of Structure and Residual Stresses in the AMg6 Alloy at Laser Shock Peening Without Coating

Application of microwave technology to extract pure sesame oil

The purpose of the study was to use microwave technology to extract pure sesame seed oils. The findings of investigations on how microwave treatment affects sesame seed yields for oil and cake are reported. It has been demonstrated that the radiation strength and duration of processing have a major impact on oil production. Studies have shown the possibility of increasing the yield of sesame oil, compared to obtaining oil with preliminary heat treatment of sesame seeds, by 1.97% by treating them with steam and subsequent treatment with microwave radiation for 12 minutes. In these circumstances, the oil output is 33.72%, the cake yield is 66.28%, and the moisture content is reduced to 3.77%. The oil content of the seeds, the intensity of the microwave radiation, and the length of the process are the primary factors affecting the amount of oil released. The best technical parameters have been determined, at which 33.72% of the oil and 66.28% of the cake are extracted.

Justification of progressive technology for drying vegetables and corn

Today, from the industrial applications point of view, getting dry food products by infrared radiation is considered the most relevant and perspective. Such properties of any object as absorption and emission of radiation in the infrared spectrum give possibility to dry them at moderate temperatures and rapidly. This technology makes it possible to gain dry items with high shelf-life due to their resistance to microorganisms. Infrared drying of products reduces drying time several times. As a result, the quality of ready items is very high and in addition ecologically pure. Also the form of cutting of raw materials before drying has some influence on time of process. The objects of study were samples of vegetables and corn planted in the experimental plot Kainar Bulak (Shymkent).During the drying process, vegetables as carrot and beet which were broken in the form of shavings reached required moisture 12.30% and 11.50% accordingly in two and half hours. Samples in the form of cubes were dried to these numbers only in three hours. Additionally, performed experiments indicate that there is no need for preliminary heat treatment (blanching) of samples. Reducing the time and temperature of heat treatment for corn also gave positive results. Thus, drying chopped vegetables and corn for further use in the food industry using infrared radiation is promising and cost-effective.

Sour milk drink technology with amarant flour

The article presents the results of a study on the production of sour milk drink with amaranth flour and cranberry puree. Sour milk drink corresponds to the modern concept of production of qualitatively new food products with the directed changes of chemical structure according to physiological needs of the person. Amaranth flour has been used in the production of innovative products as a high-protein ingredient that increases the nutritional value of products. At the first stage, a study of the functional and technological properties of amaranth flour was conducted. The parameters of preliminary heat treatment of amaranth flour were experimentally established. It was found that increasing the temperature and duration of aging amaranth flour increases its moisture-retaining properties. It is proposed to brew amaranth flour at a temperature of 90 °C for 10 minutes. In experimental studies, brewed amaranth flour in different concentrations was added to the milk base of the experimental samples: sample 2 – 1 %, sample 3 – 2 % sample 4 – 3 % sample 5 – 4 % and prepared cranberry puree in the amount of 5 %. Preparation of cranberry puree consisted of heating to t = 40 ± 2 °C, adding sugar and stirring. According to the results of the research, the amount of brewed amaranth flour in the fermented milk product was established. The most harmonious were the organoleptic characteristics with a content of brewed amaranth flour of 3 %. The technology of production of sour-milk drink with vegetable ingredients by thermostatic method is offered. Technological operations for the production of fermented milk product are as follows: acceptance and evaluation of the quality of the main and auxiliary raw materials; cleaning from mechanical impurities, separation, cooling, milk reservation; homogenization of the mixture; pasteurization and cooling of the mixture; preparation of cranberry puree; brewing amaranth flour; assembly of the mixture, application of leaven, mixing, bottling, sealing, marking; fermentation, cooling, comprehensive assessment of quality and functional properties; transportation and sale.

I solution of the heat conduction problem for computational modeling of the hydrogen content reduction in large-size forgings during antiflocken heat processing

The paper investigates problems of flocken formation in large-sized billets during heat treatment increasing hydrogen degassing. The solution of thermal conductivity problem is given, the estimation of thermal cycles at preliminary heat treatment for the subsequent solution of hydrogen diffusion problem is carried out on the example of medium-alloyed steels of 5KhNM and 20Kh3NMFA grades.

Effect of Preliminary Heat Treatment on the Formation of Structure and Mechanical Properties of Brass during Alternating Bending

Effect of Preliminary Heat Treatment on the Formation of Structure and Mechanical Properties of Brass during Alternating Bending

Effect of thermomechanical processing of building stainless wire to increase its durability

A traditional use of high cumulative reduction ratios is not effective for manufacturing wire with high performance and mechanical properties, since cold plastic deformation reduces the wire diameter, while hot deformation has its own limitations. Thus, thermomechanical treatment of rolled steel has a huge potential to reduce costs and improve product quality when used in the construction industry. Such processing allows metalworking industries to increase the economic effect due to a more complete satisfaction of the requirements for the mechanical properties of finished rolled products. The article developed a new technology for thermomechanical processing of stainless steel wire, consisting of preliminary heat treatment to obtain an austenitic structure and traditional drawing followed by cryogenic cooling. As a result of such treatment, an ultrafine-grained structure was obtained, consisting of a mixture of austenite and α-martensite, with high strength and plastic properties. To analyze the features of the obtained microstructures, modern methods of metallographic analysis were used, such as scanning electron microscopy, transmission electron microscopy, and analysis of backscattered electron diffraction patterns. The microstructure is obtained after deformation at both temperatures and consists of a mixture of α-martensite and austenite. A structure with an average grain size of 0.5 µm was obtained by drawing using cryogenic cooling, and a microstructure of 1 µm was obtained at room temperature. The results obtained allow us to expect an increase in the performance and durability of stainless steel wire, which can be used for various purposes.

Exploring the Mineral Composition of Grapevine Canes for Wood Chip Applications in Alcoholic Beverage Production to Enhance Viticulture Sustainability

This study aimed to assess the metal content of tannic extracts obtained from grapevine canes, to evaluate their suitability as wood shavings for direct infusion during the aging process of alcoholic beverages or vinegars. Traditional barrel aging is a slow and costly process that can be enhanced through direct infusion of wood chips. Our investigation focused on the pruning materials of two widely cultivated Lambrusco cultivars in the Modena (Italy) area, Ancellotta and Salamino. The grapevine chips underwent preliminary heat treatments at temperatures ranging from 120 °C to 260 °C. Tannic extracts were obtained by ethanol maceration at 80 °C for 2 h. The metal composition was determined using inductively coupled plasma optical emission spectroscopy. Generally, the metal content increased with the roasting temperature of the chips. Two exceptions were noted in the Salamino extracts, where the concentrations of Bi and Ni decreased as the roasting temperature increased. The levels of heavy metal, such as Pb and Cd, were low, posing no toxicity concerns for using infused grapevine chips during the beverage aging process. The Ni concentration slightly exceeded the limits imposed by certain regulations. Its content is likely derived from the type of soil in which the plant has grown.

Use of the Ball-Cratering Method to Assess the Wear Resistance of a Welded Joint of XAR400 Steel.

Wear-resistant steels are designed to allow for operation under extreme loading conditions. They combine large strength with resilience and resistance to abrasive wear. In stock, the steel is subjected to preliminary heat treatment. However, any further processing at temperatures higher than 200 °C results in tempering that influences the mechanical properties of the material. The presented paper aims to study changes in abrasive wear properties across the welded joint made out of this steel, and its prime novelty lies in using the ball-cratering method to test the wear resistance of the joints. To distinguish between different crystalline structures in the weld, metallographic and XRD analyses were performed that resulted in the determination of five primary zones for which wear tests were carried out. Abrasive wear rates, studied across the welded joint, indicate that the material in the HAZ has the lowest resistance to abrasive wear. Similarly, the obtained values of the wear index show decreasing resistance of the material approaching the joint axis.