Pearlite Structure Research Articles

Microstructural and tribological properties of multilayered coatings developed through heat treatment on the surface of CP-Ti

It is well known that applying NiTi intermetallic coatings on the surface of different alloys can improve their tribological behavior. In this paper, various intermetallic phases of Ni3Ti, NiTi, and NiTi2 and a Ti-rich pearlite-like eutectoid structure were in situ synthesized on the surface of commercially pure (CP) titanium grade 2. Nickel electroplating was performed on titanium samples followed by heat treatment at a temperature of 800 °C for various times up to 8 h. The formation of various phases and structures along the depth were studied using SEM, EDS and XRD. Heat treatment at a temperature of 800 °C for 4 h resulted in the formation of a multi-layered composite of Ni3Ti, NiTi, and NiTi2 intermetallic films with a thickness of 5, 9, and 2 μm, respectively. A nickel diffusion layer (NDL) with a pearlitic structure containing nanolayers of αTi-NiTi2 was also formed beneath the NiTi2 layer even after 30 min of heating. Among the different layers formed on the surface of CP-Ti, the titanium-rich NiTi (51–52 at.% Ti) showed the highest hardness of more than 400 HV. Sliding wear tests were performed under a normal load of 10 N and the surfaces of wear tracks were studied using SEM. The results showed higher wear resistance of all intermetallic layers and NDL than the titanium substrate, with the highest wear resistance for Ni3Ti top layer.

Achieving high strength and low yield ratio by constructing the network martensite-ferrite heterogeneous in low carbon steels

In this research, focusing on low-carbon steel, a martensite-ferrite heterogeneous structure dual-phase (MFDP) steel with a network morphology where ferrite is surrounded by martensite was obtained via cyclic annealing and subcritical quenching heat treatment processes. With the initial microstructure of ferrite and lamellar pearlite, a spherical pearlite and martensitic structure surrounding the ferrite was first obtained by applying the cyclic annealing process near the Ac1 temperature. Subsequently, the annealed structure was subjected to subcritical quenching heat treatment, thereby establishing a network-like martensite-ferrite dual-phase heterogeneous structure and named N-760 °C and N-780 °C. In comparison with the ferrite-martensite dual-phase steel where ferrite envelopes martensite, N-780 °C witnessed a marked increase in tensile strength and uniform elongation, while the yield ratio dropped by 20 %. Through cyclic loading and unloading tensile tests, it was found that the N-760 °C showed a more obvious heterogeneous deformation-induced (HDI) strengthening effect. The results from electron backscattering and transmission electron microscopy indicate that, in the N-760 °C, a small quantity of dislocations is produced in the ferrite due to the martensitic phase transformation prior to the tensile test. During the tensile process, as the strain increases, the ferrite undergoes significant deformation, and the intragranular dislocations re-arrange to form dislocation cells and deformation-induced grain boundaries (SIBs). Meanwhile, geometrically necessary dislocations (GNDs) accumulate at the ferrite/martensite interface. Therefore, the non-coordinated deformation between the mesh-like dual-phase microstructure offers additional HDI strengthening for MFDP steel.

Formation of requirements for impact resistance and wear resistance of grinding balls

The article presents the results of a study of the operation processes of steel grinding balls in semi-autogenous grinding mills (SAG). It was determined that the balls experience both abrasive and impact loads. The properties of steel grinding balls with the same production technology are determined by the chemical composition and the formed microstructure over the entire cross-section of the ball. Balls made using 3 different technologies were studied. The balls of sets 1 and 2 show high hardness values at the surface, sufficient to ensure good resistance to wear during operation, and a sharp decrease in hardness at a distance of ~(15–20) mm from the surface as the volume of pearlite structures increases. At the same time, the balls of the 1st and 2nd sets showed low values of impact strength and insufficient resistance to impact. The lowest hardness values from the surface to the center were observed for set 3. Also, the highest mass loss during the abrasive wear test was recorded for set 3, which is explained by the lowest hardness values. The balls of set 3 showed higher values of impact strength and no splitting during the ball-on-ball test, which is explained by the soft ferrite-pearlite structure both on the surface and across the cross section of the ball, due to the reduced carbon content and the presence of nickel in the chemical composition. At the same time, the balls from set 3 showed the worst result in terms of abrasive wear. In the course of the conducted research, it was established that for successful operation in SAG, steel grinding balls must have a surface with high hardness due to the martensitic structure and a viscous core with a ferrite-pearlite structure. A promising direction in the development of technology for the production of steel grinding balls will be to obtain a steel ball microstructure that decreases uniformly from the surface to the center, which will allow maintaining high wear resistance and increasing the resistance to ball splitting

A novel route of carburizing through microwave hybrid heating

Abstract Carburizing is a surface treatment process by diffusing carbon into the steel. These days, manufacturing industries demand highly efficient processes that consume low power. Microwave processing is a newly evolving process that consumes low power. This study proposes a novel route for carburizing mild steel (substrate) through experimental and simulation studies using a microwave heating. Charcoal powder was used as a susceptor to convert microwave energy into heat energy and to deposit carbon on the surface of the specimen. The mild steel specimens were exposed to the microwave power input of 900 W and 360 W for exposure time of 1500 s and 1980 s naming it as S2 and S3 respectively. The microstructural analysis of specimens S2 and S3 confirms the formation of pearlite structures at the surface. However, the amount of pearlite structure was significantly higher for the S3. The higher carbon content is confirmed through energy-dispersive x-ray spectroscopy (EDS) analysis of specimen S3. The average hardness of the S3 specimen was determined to be 220.8 HV, which shows an increase of 38.36% compared to the S1 (base metal). x-ray diffraction (XRD) results indicate the additional cementite peaks (Fe3C) and ferrite-confirming phase transformations for carburized samples. The wear analysis of S2 and S3 was conducted through pin-on-disk testing. The peak COF of 0.73 and 0.64 was observed for S2 and S3 respectively. The hard surface of S3 resists the penetration of the counter body to a greater extent due to the fine morphology of pearlite. From the FEM study, the maximum value of 7.96 × 10 3 (V/m) was determined at the center region for the electric field distribution in the microwave cavity, which is the optimum value for efficient heating. The maximum temperature of the mild steel obtained during the carburization process was 900 °C in 1800 s. The microwave carburizing process requires relatively less time than the conventional carburizing process which will save energy consumption.

Особливості структуроутворення заевтектоїдних сталей, легованих міддю

The structural state of pre-eutectoid steels alloyed with copper in the range of up to 28% was studied. It was established that the alloying of steel with a carbon content of 1.3% with copper in the amount of 8, 12 and 28% leads to the formation of the primary and secondary copper -phase The main metallic component of the structure of the studied copper-alloyed steels is represented by thin-plate copper pearlite with inclusions on the boundaries of the primary austenite grains of secondary cementite and secondary inclusions of the copper -phase. The results of the X-ray spectral microanalysis showed that the primary copperite of the -phase consists of 92.5% of copper and 7.1% of iron. The transition zone between the primary copper precipitate and the matrix, the distribution of chemical elements in it, was studied. The total size of the interphase zone is 0.4 μm. It was established that alloying of steels with 8-28% copper contributes to the formation of a highly dispersed structure of copper thin-plate pearlite, as well as the formation of areas with deformed microvolumes near the primary copper e-phase, which constitute a significant barrier to the movement of dislocations. Thus, a state with increased resistance to dynamic loads has been formed at the micro level. The obtained results open up the possibility of using post-eutectoid steels alloyed with copper in the corresponding highly loaded products Keywords: structure, post-eutectoid steel, alloying, thin-plate pearlite, e-phase, iron, spectrum.

Fine Structure of Lamellar Pearlite in Iron–Carbon Alloys (Review)

Fine Structure of Lamellar Pearlite in Iron–Carbon Alloys (Review)

Fracture surface microstructure and new fracture mechanism in the pearlite structure

The fracture behaviours of pearlite structures in several typical carbon steels were investigated by scanning electron microscopy (SEM). Microstructural analysis indicated that the fracture of pearlite is a mixed ductile-brittle fracture, and brittle fracture has cleavage fracture characteristics, which often occur inside the pearlite structure. The fracture surface can exhibit any orientation relationship with the ferrite/cementite interface plane in the pearlite structure. The two phases in the pearlite structure (ferrite (α-Fe) and cementite (θ-Fe3C)) are fine grains rather than single-crystal platelets. The cleavage fracture mechanism in any direction of pearlite structure occurs due to the fine grain substructure.

Microstructural and elemental analysis of flow lips of heavy haul curved rails affected by deformation driven phase transformation

A combination of optical imaging (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atom probe tomography (APT) was used to examine the white etching layer (WEL) and brown etching layer (BEL) formed in the flow lip region of a heavy haul curved rail. These flow lips eventually serve as crack initiating regions, leading to reverse detail fractures. OM distinctly identified the WEL/BEL region based on light contrast, while SEM micrographs identified a fine-grained structure within the WEL with intermittent patches of a deformed pearlitic structure. SEM images of the WEL/BEL indicate that the fraction of cementite patches was higher in the BEL region than in the WEL. TEM investigations revealed the presence of martensite/nano-crystalline ferrite along with newly formed austenite and cementite particles in the WEL and the BEL. The ferrite/martensite grain size was much finer in the WEL than in the BEL. The lath morphology of martensite was observed in the BEL, whereas a mixed morphology of lath and twinned martensite was observed in the WEL. APT studies show no Mn/Si partitioning in WEL/BEL along with C-concentrations ranging from 10 to 15 at.% and up to 20 at.% in the WEL and BEL respectively. The synergistic effect of elevated wheel-rail contact temperatures and severe plastic deformation dictated the overall microstructural evolution of the BELs and WELs on the outer rail surface in the flow lip.

Characterizing pearlite transformation in an API X60 pipeline steel through phase-field modeling and experimental validation

This study explores the microstructural characterization of pearlite phase transformation in high-strength low-alloy API X60 steel, which is used in pipelines. Understanding the formation, phase percentages, and morphology of the pearlitic phase is crucial since it affects the mechanical properties of the considered steel. In this research, a phase-field model, particularly the Cahn–Hilliard approach, was used in order to simulate the formation and morphology of the pearlite phase in response to different heat treatments. Both double- and triple-well potentials were considered for comprehensively studying pearlite’s morphology in the simulations. The simulation results were then compared with experimental outcomes obtained by metallography and field-emission scanning electron microscopy analyses. Considering the double-well potential can help simulate only two phases, ferrite and cementite, which is less compatible with the experiment results than the triple-well potential, which gives the possibility of simulating a three-phase microstructure, ferrite, cementite, and austenite, and a better match with experimental data. The study revealed that as the cooling rate increases, the interlamellar spacing and layer thickness decrease. Additionally, the difference between experimental and simulation results using triple-well potential was approximately ∼10%. Therefore, triple-well potential formulation predictions have better agreements with experimental results for the development circumstance of pearlitic structures.

Microstructural study of additively-manufactured carbon steel-stainless steel 316L - Inconel 625 functionally graded material: Simulation and experimental approaches

This study aims to analyze the microstructure and present phases of functionally graded carbon steel - stainless steel 316L - Inconel 625 using experimental methods and computational software (JMatPro). Both FE-SEM and SEM-EDS equipment were employed to evaluate the materials. The JMatPro software accurately simulated the present phases and their formation temperatures. The microstructure in the plain carbon steel part formed the ferrite phase at 900 °C, while a small amount of pearlite structure formed at 700 °C, remaining stable at ambient temperature. Chromium phase in stainless steel 316 L layers increased with solidification, with a higher increase in the delta ferrite phase. Inconel 625 at 1130 °C, the Laves nucleated with austenite, stable up to ambient temperature. As liquid decreased, niobium and molybdenum accumulation increased, potentially leading to Laves formation. The significant increase in niobium content at the interface of stainless steel 316L-Inconel 625 is attributed to an increase in iron content. The research indicated a good correlation between the observed and predicted microstructures.

Influence of sample extraction location on thermal desorption spectroscopy from a heat-resistant 13CrMo4-5 steel plate and correlation with microstructure features

Thermal desorption spectroscopy (TDS) is a highly sensitive and widely used method to directly measure the total hydrogen concentration and indirectly assess the hydrogen trapping sites and mechanisms from the spectra features in steels. Thus, there is a need to investigate the influence of sample location from a 5 mm plate of hot-rolled heat-resistant structural steel on TDS spectra. Via a new highly sensitive and specific correlation coefficient (microToH), the TDS results are correlated with low-angle grain boundaries volume fraction, grain size with different misorientation thresholds, microhardness, and geometrically necessary dislocations at different densities.The results indicate that sample location influences 133 % and 62 % in the hydrogen desorption of peak 1 (at 515 K), and total hydrogen concentration via the influence of peak 2 (at 634 K), respectively. Thus, sample location needs to be considered as one relevant aspect in a research plan based on TDS analysis. The influence on peak 3 (at 762 K) was found to be negligible as it is related to the first exothermic peak of the heating cycle, associated with carbide precipitation phenomena. The individual grain analysis performed with high-resolution adaptive DMM and GND maps emphasises the accumulation of the deformation in the ferritic domain at the vicinity of the pearlite structures.

Analysis of the Influence of Contact Stress on the Fatigue of AD180 High-Carbon Semi-Steel Roll

In this study, to investigate the problem of contact fatigue and the damage mechanism of an AD180 high-carbon semi-steel roll, rolling contact fatigue tests were conducted using specimens cut from the periphery of a roll ring. These specimens were characterized under different contact stresses using SEM, a profile system, an optical microscope, and a Vickers hardness tester. The results indicates that the main forms of fatigue damage of an AD180 high-carbon semi-steel roll are peeling, pitting corrosion, and plowing. Moreover, the surface of the roll exhibits delamination and plastic deformation characteristics under high contact stress. Meanwhile, the size and depth of peeling, as well as the amount of pitting corrosion, increase with the contact stress. Peeling is mainly caused by a crack that originates at the edge of the specimen surface and propagates along the pearlite structure and the interface between pearlite and cementite. High contact stress can lead to an increase in the crack propagation depth and angle, resulting in the formation of larger peeling. Under cyclic loading, the near-surface microstructure of the specimen hardens due to grain refinement and dislocation strengthening, and the depth of the hardened layer increases with the increase in contact stress. When the contact stress reaches 1400 MPa, the near surface structure of the specimen changes from pearlite to troostite.

Influence of hot plastic deformation on properties of the carbon steel

Purpose. Determination of the influence of hot plastic deformation degree on the set of carbon steel properties. Methodology. Steel with 0.6 % carbon was used for the study. The steel structure corresponded to the state after compression at 1,240 °C. Mechanical properties were determined by the tensile curve, friction stress of the ferrite crystal lattice and resistance of interphase boundary pearlite to propagation of deformation were estimated. Findings. Depending on the structural state of austenite, dispersion of pearlite colonies is accompanied by different rates of change in the properties of carbon steel. For pearlite formed from austenite after annealing, the strain hardening coefficient and maximum ductility are inversely proportional. For pearlite formed from austenite with preserved substructure after hot deformation, the strain hardening coefficient and maximum ductility are related through the proportional relationship. Originality. Preservation of the substructure of hot-deformed austenite affects propagation deformation in pearlite of the steel. Against the background of decreasing friction stress of the ferrite crystal lattice, there is an increase in resistance of ferrite-cementite boundary of the pearlite to the spread of deformation. Practical value. For carbon steels with a pearlite structures, the accelerated increase in ductility from maintaining the proportion of hot work hardening of the austenite will improve technology for manufacturing rolled products of large sections. When producing thermally strengthened rolled products, achieving a simultaneous increase in strength and plastic properties is ensured by increasing ability of metal to strain hardening.

Effect of two-stage heat treatment on the microstructure and mechanical properties of high chrome austenitic manganese steel

In this research, heat-treatment was used to determine changes in the microstructure and mechanical characteristics of austenitic manganese steel equivalent to ASTM A128-C. Carbide formed in as-cast conditions is transformed into dispersed hardened austenite to increase the toughness of the material because it can inhibit dislocation movement. Heat treatment is carried out in two heating stages. The first stage of heating was carried out at a temperature of 625°C with a holding time varying by 2.5, 3.5, and 4.5 h, and the second stage was carried out at a temperature of 1000°C with a constant holding time of 1.5 h. Microstructure observations were carried out to observe the structural morphology and carbide transformation in both the first and second stages of heating. Tensile and hardness tests were also carried out to determine the mechanical properties and their effect on two-stage heating. The research results show that the pearlite structure is formed in the first stage of heating with different lamella thicknesses. With the help of ImageJ software, the measured pearlite fraction was higher as the holding time increased in the first stage of heating. This affects the morphology of the carbide colonies formed in the second stage of heating. The higher the pearlite fraction, the more uniform the morphology of the carbide formed with round shapes that are more evenly distributed. These dispersed carbide colonies can increase the toughness of the material up to 17 times higher than the as-cast condition obtained through mechanical testing.

A chip formation mechanism taking into account microstructure evolution during the cutting process: Taking compacted graphite iron machining as an example

Compacted graphite iron (CGI), a prototypical heterogeneous material, potentially demonstrates distinctive cutting deformation behaviours attributed to the random distribution of graphite and performance differences between graphite and the matrix, which have not yet received adequate attention. This study focuses on the influence of the microstructure characteristics of CGI on the formation of serrated chips. The morphology of the serrated chip segments during the orthogonal turning of CGI was observed in detail, the microstructures of the chip roots were characterised and analysed using various techniques, and a finite-element cutting simulation model considering the microstructural characteristics of CGI was developed. Results suggest that the formation of serrated chips in CGI is influenced by periodic and aperiodic brittle fractures, referred to as quasi-periodic brittle fractures, which are controlled by the distribution of graphite in CGI. This results in variations in the morphology and dimensions of the serrated chips in CGI. Plastic deformation is concentrated in a triangular deformation zone (TDZ) near the tool-chip interface, which is broader than the conventional secondary deformation zone. The experimental and simulation results revealed the reasons for the formation of the TDZ and emphasized the critical role of graphite in the formation of serrated chips in CGI. The graphite particles near the tool-chip interface promoted plastic deformation along the interface owing to the principle of minimum energy and restricted deformation perpendicular to the interface due to its structure, leading to the formation of the TDZ. The influence of graphite on material flow and the formation of the TDZ during the formation of serrated chips in CGI is a novel discovery. The microstructure evolution of the pearlite matrix in CGI caused by cutting deformation was analysed. The results demonstrate that the distinctive deformation behaviour of CGI contributes to the fragmentation of the pearlite structure, grain refinement, and increased dislocation density in the TDZ. Finally, the influence of the serrated chip formation mechanism on chip morphology and cutting force in CGI was discussed. These findings offer significant scientific insights and contribute to the fundamental understanding of the chip formation process in CGI.

PENGARUH QUENCHING SETELAH PENGELASAN TERHADAP KOROSI DI BAWAH INSULASI MEDIA AIR LAUT PADA BAJA A36

Corrosion in low-carbon steel is a significant issue in the industrial world, particularly in the oil, gas, refining, and chemical industries, as it leads to substantial financial losses. The total losses experienced by companies in Indonesia are estimated to reach 2-5% of the country's GDP. Corrosion arising from insulation damage, known as Corrosion Under Insulation (CUI), is challenging to detect but has a profound impact on industrial processes. Welding quality and corrosion resistance can be improved through post-weld heat treatment (PWHT). This research aims to investigate the influence of rapid cooling after welding low-carbon ASTM A36 steel on corrosion events under insulation using the "Water Immersion" method with seawater from the Muntok area, Bangka Belitung Islands Province, for 7 and 14 days. The welding process is performed using shielded metal arc welding (SMAW). Heat treatment is applied at 880°C for 60 minutes, as determined by the carbon equivalent calculation, followed by rapid cooling in seawater. Testing includes chemical composition analysis, non-destructive testing with dye penetrant on the welds, Brinell hardness testing, corrosion rate calculations, charpy impact testing, and metallography observations. The research results indicate that quenching enhances hardness and toughness while affecting the corrosion rate of the material after corrosion immersion, both with and without insulation. Material immersion exhibits a corrosion rate inhibition on the 14th day due to the formation of an oxide layer that hinders further degradation. Metallography observations reveal that after welding, phases formed include pearlite, acicular ferrite, and widmanstatten structures.

Effects of Heat Treatment on Microstructures and Mechanical Properties of a Low-Alloy Cylinder Liner.

Cylinder liners, considered a crucial component of internal combustion (IC) engines, often require excellent mechanical properties to ensure optimal engine performance under elevated temperatures, pressures, and varying loads. In this work, a new low-alloy cylinder liner, incorporating a low content of molybdenum, copper, and chromium into gray cast iron, was fabricated using a centrifugal casting process. Subsequently, the heat treatment processes were designed to achieve bainite microstructures in the cylinder liner through rapid air cooling, isothermal transformation, and tempering. The effects of different air-cooling rates and tempering temperatures on the microstructure evolution and mechanical properties of cylinder liner were investigated. The results revealed that during the supercooled austenite transformation process, rapid air cooling at a rate of 14.5-23.3 °C/s can effectively bypass the formation of pearlitic structures and directly induce the formation of bainite structures. Once the temperature exceeded 480-520 °C, hardness and tensile strength increased with the temperature increase owing to the enhancement of the lower bainite content, the reduction of residual austenite, and the precipitation of the fine hard carbides in the matrix. With temperatures above 520-550 °C, the carbide and lower bainite organization coarsened, thereby reducing the hardness and tensile strength of the material. Therefore, the optimal heat treatment parameters were rapid cooling at 14.5-23.3 °C/s rate to obtain bainite, and tempering of 480-520 °C for finer and more uniform bainite. In addition, the results of the characterization of the mechanical properties of the cylinder liner after heat treatment showed that the hardness, tensile strength, and wear resistance were improved with the refinement of the bainite.

MULTIFRACTAL ANALYSIS OF THE INFLUENCE OF CHROMIUM-NICKEL CAST IRON STRUCTURE ON ITS QUALITY CRITERIA

The influence of the structure of cast irons on their hardness was studied using multifractal analysis. The spectrum of statistical dimensions of the cast iron microstructure was calculated using the Renyi formula. The hardness of chromium-nickel cast iron was determined at three points of the sample. It was found that the pairwise correlation coefficients for predicting hardness by traditional structure characteristics (length, diameter, area) were R2= 0.73...0.87. When assessing hardness indicators by multifractal characteristics, the correlation coefficients are 0.78...0.88 for the pearlite structure with flake graphite and 0.81...0.93 for the pearlite structure with spherical graphite. The sensitivity coefficients of the hardness indicators of СПХН-43 rolls to the information and correlation dimensions of carbides, as well as to the fractal and statistical D-100 dimensions of flake graphite were determined. The sensitivity of hardness indicators to the fractal and statistical D100 dimensions of carbides and to the fractal and correlation dimensions of flake graphite was determined for СПХНФ-47 rolls. Based on the results obtained, an approach to assessing the hardness of СПХН-43 and СПХНФ-47 rolls was developed, which includes: 1). Determination of the statistical dimension spectrum of the cast iron structure elements. 2). Determination of the sensitivity coefficients of hardness indicators to the spectrum of dimensions of structural elements. 3). Creation of a mathematical model for predicting the hardness of rolls. The considered approach can be interpreted as an alternative method for assessing the quality criteria of cast irons based on the analysis of their structure.

Evolution of the Lamellar Pearlite Structure of Rail Steel under Tension

Evolution of the Lamellar Pearlite Structure of Rail Steel under Tension

Study of the influence of the structure of rolled iron on its hardness

Problem. The influence of the structure of cast irons on their hardness was studied using multifractal analysis. The spectrum of statistical dimensions of the cast iron microstructure was calculated using the Renyi formula. Materials and methods. The hardness of chromium-nickel cast iron was determined at three points of the sample. Results of experiments. It was found that the pairwise correlation coefficients for predicting hardness by traditional structure characteristics (length, diameter, area) were R2 = 0.73...0.87. When assessing hardness indicators by multifractal characteristics, the correlation coefficients are 0.78...0.88 for the pearlite structure with flake graphite and 0.81...0.93 for the pearlite structure with spherical graphite. The sensitivity coefficients of the hardness indicators of СПХН-43 rolls to the information and correlation dimensions of carbides, as well as to the fractal and statistical D-100 dimensions of flake graphite were determined. The sensitivity of hardness indicators to the fractal and statistical D100 dimensions of carbides and to the fractal and correlation dimensions of flake graphite was determined for СПХНФ-47 rolls. Conclusions. Based on the results obtained, an approach to assessing the hardness of СПХН-43 and СПХНФ-47 rolls was developed, which includes: 1). Determination of the statistical dimension spectrum of the cast iron structure elements. 2). Determination of the sensitivity coefficients of hardness indicators to the spectrum of dimensions of structural elements. 3). Creation of a mathematical model for predicting the hardness of rolls. The considered approach can be interpreted as an alternative method for assessing the quality criteria of cast irons based on the analysis of their structure.