Rolling Heat Research Articles

Hybrid Carbon Black/Silica Reinforcing System for High-Performance Green Tread Rubber.

Silica, as a high-quality reinforcing filler, can satisfy the requirements of high-performance green tread rubber with high wet-skid resistance, low rolling resistance, and low heat generation. However, the silica surface contains abundant silicon hydroxyl groups, resulting in a severe aggregation of silica particles in non-polar rubber matrix. Herein, we explored a carbon black (CB)/silica hybrid reinforcing strategy to prepare epoxidized natural rubber (ENR)-based vulcanizates. Benefiting from the reaction and interaction between the epoxy groups on ENR chains and the silicon hydroxyl groups on silica surfaces, the dispersion uniformity of silica in the ENR matrix was significantly enhanced. Meanwhile, the silica can facilitate the dispersity and reinforcing effect of CB particles in the ENR matrix. By optimizing the CB/silica blending ratios, we realized high-performance ENR vulcanizates with simultaneously improved mechanical strength, wear resistance, resilience, anti-aging, and damping properties, as well as reduced heat generation and rolling resistance. For example, compared with ENR vulcanizates with only CB fillers, those with CB/silica hybrid fillers showed ~10% increase in tensile strength, ~20% increase in elongation at break, and ~20% increase in tensile retention rate. These results indicated that the ENR compounds reinforced with CB/silica hybrid fillers are a promising candidate for high-performance green tread rubber materials.

A real-time temperature field prediction method for steel rolling heating furnaces based on graph neural networks

In the billet reheating process during steel rolling, the real-time and accurate prediction of the temperature field is a prerequisite for the dynamic regulation of the heating process, which is crucial for ensuring the quality of billet reheating and reducing the energy consumption of the reheating furnace. The most commonly used finite element thermal field simulation and analysis methods are unable to meet the demand for real-time prediction under dynamic working conditions. Furthermore, traditional machine learning methods struggle to handle irregular data that includes spatial location information, resulting in inaccurate temperature field predictions, which in turn affect the furnace control efficiency and the quality of the product. In light of these limitations, this study proposes a Graph Neural Network (GNN)-based temperature field prediction method for steel rolling reheating furnaces. This method considers the interactions between the nodes within the reheating furnace and constructs a temperature field topology graph to effectively capture these interactions, including heat conduction and convection. Additionally, in the feature fusion and state updating mechanism of the model, we introduce process parameters, such as the air-fuel ratio, as additional inputs to enhance the ability of the GNN to handle complex variables. This enables real-time accurate simulation of the internal temperature distribution of the reheating furnace. The experimental results demonstrate that the model prediction error is controlled within 2.9 % and the response time is maintained within 20 ms, thereby validating the reliability and efficacy of the method in practical applications.

Influence of thermomechanical treatment on recrystallization and softening resistance of Cu−6.5Fe−0.3Mg alloy

The recrystallization and softening resistance of a Cu−6.5Fe−0.3Mg (mass fraction, %) alloy prepared by Process 1 (cold rolling heat treatment) and Process 2 (hot/cold rolling heat treatment) were studied using Vickers hardness tests, tensile tests, scanning electron microscopy and transmission electron microscopy. The softening temperature, hardness and tensile strength of the alloy prepared by Process 2 were 110 °C, HV 15 and 114 MPa higher, respectively, than those of the alloy prepared by Process 1 after aging at 300 °C. The recrystallization activation energy of the alloys prepared by Process 1 and Process 2 were 72.83 and 98.11 kJ/mol, respectively. The pinning effects of the precipitates of the two alloys on grain boundaries and dislocations were basically the same. The softening mechanism was mainly attributed to the loss of dislocation strengthening. The higher Fe fiber density inhibited the average free migration path of dislocations and grain boundary migration in the alloy, which was the main reason for higher softening temperature of the alloy prepared by Process 2.

High bonding strength of Ti /steel clad plates prepared by a developed electromagnetic induction heating followed by rolling

Titanium/steel clad plates exhibit significant potential for industrial applications, such as petrochemical and aerospace, due to their combined advantages of two components. In the conventional hot rolling process, the formation of brittle intermetallic compounds (IMCs) had a detrimental effect on the mechanical properties of Ti/steel clad plates. Therefore, the present study proposed an electromagnetic induction heating rolling (EIHR) technique for efficiently fabricating Ti/steel clad plates with high bonding strength at a relatively low temperature, while avoiding the formation of brittle IMCs. Additionally, a pure iron DT4 interlayer with good fluidity was introduced between Ti and steel, which can further enhance both the interface bonding strength and elongation of the clad plates. Based on the electron backscattered diffraction characterization results of the interface, it was found that the addition a DT4 interlayer facilitated dynamic recrystallization of steel side and led to a reduction in dislocation density. Moreover, a pronounced {100}〈011〉 rotational cube texture was evident on the (100) pole figures as a result of substantial plastic deformation during the rolling process. Finally, the relationship between interface microstructure and mechanical performance was established.

Relating rolling contact fatigue (RCF) life to the microstructure evolution in aerospace grade bearing steels: A comparison of Cronidur-30 with AISI 440C

This article presents an extensive analysis of the microstructural evolution under various heat treatment conditions, mechanical properties (hardness), and rolling contact fatigue (RCF) life assessment and sub-surface crack analysis are studied on high nitrogen bearing steel Cronidur-30(Cr-30). An optimum solutionising temperature range has been identified which ensures desirable hardness as well as low retained austenite content. The microstructure consists of primary M2 (C, N) and secondary M23C6 carbides. Sizes of carbides in Cr-30 are significantly smaller than in AISI 440C and this plays a critical role in enhancing the RCF life of Cr-30. A larger area fraction of fine carbides results in branches and subsequent sub-branches of cracks in Cr-30 steel. However, the AISI 440C sample exhibits extensively interconnected cracks due to the presence of larger carbides. The tempering response of Cronidur-30 exhibited a peak hardness of 61 HRC at both lower (150 °C) and higher (475 °C) temperatures. Higher temperature tempering showed L1 life improvement of over 0.5 fold compared to lower temperature tempering.

Optimization and sensitivity analysis of heat transfer for Powell–Eyring fluid between rotating rolls with temperature-dependent viscosity: A mathematical modeling approach

This study explores the flow of a non-Newtonian fluid between two rolls that are counter-rotating at the same speed and of equal size. The fluid's viscosity depends on temperature, and we investigate its theoretical impact on the thickness of the sheet and other engineering parameters relevant to the process. We derive non-dimensional mass and momentum balance equations using suitable transformation and the lubrication approximation theory. The expressions for velocity distribution, pressure gradient, flow rate, temperature profile, and pressure fields have been obtained by utilizing the perturbation method. After obtaining these expressions, we compute engineering quantities such as the roll separation force, streamline, Nusselt number, and the power input required to drive both cylinders based on the system's kinematical and geometrical parameters. We also obtain numerical solutions using the finite difference method and built-in (BVP method) in Maple. Further, we use response surface methodology and analysis of variance to determine what the mathematical models mean and whether they are good enough for sensitivity and optimization analysis of the heat transmission and roll separation force. Using statistical tools such as the R2, we determine that our Nusselt number and roll separation force provide the best solution for the considered model. Additionally, it has been observed that as the Weissenberg number increases, velocity tends to rise; conversely, velocity decreases with a higher velocity ratio. Also, the temperature profile is notably influenced by the Brickman number and increases with the increase in the Brickman number. It has also been noted that as the values of velocities ratio increase, the separation points shift toward the nip region, while concurrently, the coating thickness decreases. Furthermore, we also demonstrate that compression between analytical and numerical solutions for the considered problem of fluid flow, which suggests that the results presented here are reasonable. Finally, we compare our work with published studies to validate our findings. Hence, these factors help in an efficient fluid coating process and improve the substrate life.

A Multipath Process-Based Inherent Strain Method for Prediction of Deformation of Hull Plate for Integrated Heating and Mechanical Rolling Forming Process

Integrated heating and mechanical rolling forming (IHMRF) has recently been introduced for manufacturing complex curvature hull plates. It fabricates the target curved plate by sequential loading along the multipath. Accurate and efficient prediction of the deformation of the plate is the basis for developing the process planning and ensuring the quality of the forming. The inherent-strain method is ideal for this purpose, but its prediction accuracy needs to be improved. This paper proposes a multipath process-based inherent-strain method (MPISM), which considers the effect of the sequential loading process of the multipath on plate deformation. First, the effect of loading paths near the plate edge was investigated, which in turn clarified the rationale for obtaining the inherent strain only in the plate center. Secondly, a strain correction strategy was established by analyzing the variation pattern of the inherent strain caused by the crossing or proximity of the previous path and the subsequent path. This allowed the effects of the loading process to be taken into account in the elastic analysis. Based on the plate-and-shell theory, the idea of an equivalent inherent strain distribution is also presented. This makes the loading of inherent strains more accurate in the elastic finite-element model. MPISM predictions and experimental results show good agreement. Compared with the thermo-elastic–plastic finite element method, the MPISM substantially improves efficiency while maintaining accuracy. Compared with the original inherent-strain method, the MPISM is more accurate in terms of deformation magnitude prediction.

Improving joint performance of friction stir welded 2195-O Al–Li alloy by post-weld heat treatment and rolling deformation

Post-weld heat treatment and rolling deformation are used to improve the mechanical properties of 2195-O Al–Li alloy friction stir welding (FSW) joints, and the effects on the grain structure, precipitation behaviors, hardness distribution, and tensile performance are discussed. Microstructural characterization was conducted using scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM). Mechanical properties were measured by hardness test and tensile test. Results show that coarse precipitates are subjected to various degrees of dissolution after FSW. Solution treatment following artificial aging (SAA) and 40% rolling deformation + SAA treatment (R40-SAA) enables the dissolution of coarse precipitates completely and precipitation of strengthening phases (T1 and θ′) in the nugget zone (NZ), thermo-mechanically affected zone and heat-affected zone (HAZ). These strengthening precipitates have little difference in precipitation behavior after SAA and R40-SAA treatment and remain consistent across all regions, resulting in joint hardness change a little between these two joints with a homogeneous distribution. The change in precipitates leads to an increase in hardness and enhances both the SAA joint strength and the R40-SAA joint strength to 503 MPa and 528 MPa (superior to the original joints by 309 MPa and 334 MPa, respectively), respectively. The SAA joints fracture in the NZ resulting from the development of AGG, and develop an intergranular fracture morphology with an elongation of 4.2%. The R40-SAA joints have an elongation of 7.2% due to the generation of uniformly fine grains in the NZ, and fail in the HAZ exhibiting a brittle fracture mechanism.

Influence of production technology of thick plate rolled from shipbuilding steel of strength level 500 on structure parameters and workability characteristics at low temperatures

The influence of manufacturing technology of low-alloy steel with yield strength not less than 500 MPa on structure parameters has been studied. Under industrial conditions, two 50 mm thick sheets were produced by different technologies: 1) hot rolling followed by furnace quenching and high-temperature tempering; 2) quenching from rolling heating followed by high-temperature tempering. By means of optical, scanning and transmission electron microscopy the structural features of steel were revealed. Standard mechanical properties and low-temperature serviceability characteristics were determined.

Equivalent load model for the numerical simulation of integrated induction heating and mechanical rolling forming of curved hull plates

Equivalent load model for the numerical simulation of integrated induction heating and mechanical rolling forming of curved hull plates

Preparation of AlMgSi1 (6082) aluminum alloy for the study of mechanical and physico-chemical properties in the rolling process

The study is devoted to the preparation of the AlMgSi1 (6082) aluminum alloy for the study of its mechanical and physico-chemical properties under rolling conditions. The purpose of the work is to develop a methodology for preparing an alloy that provides reproducible analysis of its properties. The main directions include the study of rheological and plastic properties of the material, as well as thermal effects during deformation. The scientific significance of the work lies in the analysis of the effect of heat treatment and deformation parameters on the plastic fluidity and corrosion resistance of the alloy. The practical significance lies in improving the quality of materials for various industrial applications. The methodology included experiments with heat treatment and rolling, analysis of the microstructure and mechanical properties of the alloy. The tests were carried out on samples at different temperatures and strain rates using the STD 812 torsion plastomer. The results showed that the plasticizing stress of the alloy increases with deformation at low temperatures and decreases at high temperatures. The conclusions confirm the significant influence of temperature and strain rate on the properties of the alloy.

Bio-based Eucommia ulmoides gum composites for high-performance engineering tire applications

In this work, bio-based Eucommia ulmoides gum (EUG)/natural rubber (NR)/styrene-butadiene rubber (SBR) composites are successfully fabricated through physical blending. The influence of sulfur (S) and EUG content on the crystallization characteristics, static and dynamic mechanical properties of the composites is systematically investigated. Furthermore, the impact of the cross-linking network structure on the crystallization behavior of EUG is examined, and the application of EUG/NR/SBR composites in engineering tires is explored. The results reveal that with the increasing of EUG content, the composites exhibit enhanced wear resistance and cut resistance, as well as reduced heat generation and rolling resistance. Specifically, in comparison with NR/SBR composites, the dynamic temperature rise, wear resistance, and dynamic cutting amount of EUG/NR/SBR (20/40/40) composites decreased by 14.7%, 17.1%, and 11.2%, respectively, while the fatigue life of the composites improves by 33%. This work provides valuable guidance for fabricating and applying high-performance bio-based EUG composites in engineering tires.

Effects of additional heat treatment on struc-ture and microhardness of high-strength steel shipbuilding

The paper studies kinetics of austenitic grain growth (when heating) and the peculiarities of phase transformations (when cooling) that depend on the manufacturing technology of high-strength steel. The method of vacuum etching has been applied to reveal former austenitic grain boundaries in steel. It is shown that the necessary homogeneous structure in morphology and dimensions of structural elements in martensitic steels is formed under the influence of additional quenching from furnace heating with tempering after quenching from rolling heating.

Structure and mechanical properties of shipbuilding steel produced by direct laser deposition and hot rolling

The structure and properties of specimens obtained by direct laser deposition from 09CrNi2MoCu steel have been investigated. The results of anisotropy of properties and structural heterogeneity induced by high rate of obtaining cold-resistant steel specimens are presented. It is shown that the content of residual austenite and cementite in the steel structure, after direct laser deposition at the boundaries of fusion rolls is significantly higher, which contributes to anisotropy. Rolling of the deposit specimens was carried out in order to reduce the anisotropy of properties and to increase the strength and plastic properties. In the work two rolling technologies are considered: hardening from furnace heating and from rolling heating, as well as the next high tempering.

The Effect of Water Jet Overlaps in a Descaler on the Quality of Surface of the Hot Rolled Steel

Hot rolling is a highly efficient steel processing method involving the heating and subsequent rolling of semi-finished cast products within mills; however, heating results in the formation of an undesirable, inhomogeneous oxide layer on the surface. Removal of this layer, known as scales, prior to rolling is essential to prevent scales from being rolled into the surface. The scales are removed in the descaler. Most descalers use multiple high-pressure hydraulic descaling nozzles with overlapping sprays. This setting can cause excessive cooling in the overlap area, uneven descaling of the surface, and the presence of residual scales. It can also result in uneven cooling at the finishing line. This study illustrates a typical nozzle configuration commonly used in industrial plants in the hydraulic descaling process and compares its results with a new configuration. The research focuses on examining the overlap area and the washout area of the sprays. The goal is to address the inhomogeneous descaling problem and propose procedures to prevent residual scales. It was shown that one of the problematic areas is the washout area, where the average thickness of the remaining scales was more than four times higher than other descaling areas. Reducing the offset angle has proven to be a good way to eliminate the washout area and achieve a homogeneous descaling process.

The concept of a complex digital twin of a furnace for metal heat processing

A number of mathematical models, digital twins and diagnostic systems are considered, which are used for individual processes and elements of flame furnaces. An idea was put forward about the expediency of creating a complex digital twin, which simultaneously takes into account the main processes in metal heat processing (heating for rolling or heat treatment) in a flame furnace. A conceptual definition of the structure and interconnection of the elements of a complex digital twin of a furnace for metal heat processing is carried out. It is substantiated that the data to ensure the operation of the digital twin are divided into two groups: constantly or periodically measured values and data that are unchanged. The minimum set of quantities, the measurement of which is necessary for the operation of the proposed complex digital twin of the furnace, is determined. A list of objective data about the unit and the technological process, which are unchanged over a long period of operation, is also compiled. At the same time, a scheme for organization the interaction of special computing units has been developed, which allows to achieve high accuracy in solving the traditional problem of mathematical modeling of metal heat processing ‒ determining the metal temperature field. To achieve this result, computing units are used to identify the parameters of all processes that affect the solution of the problem: the value of air suction into the furnace chamber and along the smoke path, the value of the recovery coeffi-cient, the oxygen consumption for the oxidation of the metal surface, the average heat flux density absorbed by the metal surface. Special blocks are also provided for diagnosing the state of the heat exchanger, fan, smoke path, chimney and elements of the mechanical equipment of the furnace. Ultimately, top-level blocks are provided that allow, based on the processing of information from all the basic blocks of the complex digital twin, to analyze the energy efficiency of the furnace unit, obtain the technical and economic characteristics of its operation, as well as to issue recommendations to clarify the current parameters of technological processes and maintenance of equipment elements.

Synthesis of sonochemical chloroacetated natural rubber and its potential use in passenger car tire tread

This article describes the preparation of chloroacetated natural rubber (CNR) through the epoxidation of natural rubber (NR) latex with performic acid, followed by the reaction with chloroacetic acid. Ultrasound waves were utilized to accelerate the epoxidation reaction. The CNR samples obtained at various epoxidation durations were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, and differential scanning calorimetry techniques. Results showed that the chloroacetate content in CNR increased with increasing epoxidation time, i.e., the chloroacetate contents were 17.4, 18.5, and 19.7% at epoxidation times of 30, 45, and 60 min, respectively. The prepared CNR samples were then employed to replace NR in silica-filled tire tread compounds based on a 70/30 solution styrene butadiene rubber (SSBR)/NR blend. It was found that, compared with NR, CNR provided significantly higher rubber-silica interaction, leading to improved mechanical and dynamic properties. Such replacement not only reduced heat build-up and rolling resistance, but also increased the wet grip index, which is highly beneficial for the production of high-performance passenger car tires. It could be observed that the improvements in rubber properties and tread performance were more obvious when the chloroacetate content of CNR was increased, probably due to the enhanced rubber-filler interaction, as demonstrated by the increased bound rubber content.

On-line heating rolling behavior of Mg9999 sheets under large single pass reduction

Pure magnesium foil has a great potential for rechargeable magnesium battery anode application, the formation of edge crack and break during Mg sheet rolling highly decreases the yield and thus increase the cost. In this paper, pure magnesium sheets of different thicknesses (0.3 mm, 0.4 mm, 0.5 mm and 0.6 mm) were prepared from 1 mm pure magnesium sheets by on-line heating rolling in a single pass. The edge cracking and breaking behavior of pure magnesium sheets were characterized by scanning electron microscope (SEM), X-ray diffractometer (XRD), electron backscatter diffractometer (EBSD), energy dispersive spectroscopy (EDS) and laser scanning confocal fluorescence microscope (LSCM). The results show that the number of edge cracks of pure magnesium sheets increases with the increase of rolling reduction. As the rolling reduction increases to 70%, due to the severe edge crack of 0.3 mm thick sheet and the formation of grooves on the magnesium sheet surface, the breaking of pure magnesium sheets occurs. The mechanism of edge cracking and breaking of ultra-thin pure magnesium rolled sheet is discussed.

Identification of the nature of defects arising in the production of continuously cast pipe billets for the oil and gas industry

The paper presents the results of studies of defects that occur in the production of continuously cast pipe blanks for the oil and gas industry. It is shown that the use of the technology of continuous casting of pipe billets in comparison with the traditional methods of pouring liquid steel into a mold has a number of advantages, among which is the high productivity of the technological process. However, it was noted that in many cases, an abnormally high degree of contamination with non-metallic inclusions is observed in the structure of the steel of continuously cast pipe billets. It was revealed that the largest inclusions are oxides of silicon and manganese. On the surface of the pipes, there are defects in the form of oxide spots, near which there are large non-metallic inclusions. On the surface of the oxide spot, the presence of iron oxides in the form of scale is found, which is a consequence of the secondary oxidation of the metal by air oxygen. A mechanism for the development of oxide spots and decarburized strips in pipe billets has been determined, which consists in the formation of defects in the form of scratches and cracks on the surface before rolling. These defects during heating for rolling lead to the oxidation of the metal and the formation of scale on the surface of the pipe blanks. The results of experimental studies on the development of recommendations for improving the quality of the initial metal of seamless pipes for the oil and gas industry are presented. The study of the microstructure of steel and the assessment of its contamination with non-metallic inclusions were carried out on optical and electron microscopes, and the mechanical properties of pipe blanks were studied by standard methods

Hierarchical structure optimal setting approach for production indexes of the rolling heating furnace temperature field

In order to improve the optimal setting temperature problem to achieve the global optimum of product performance, costs and benefits. In this article, a hierarchical structure optimal setting approach of production indexes for the rolling heating furnace temperature field (RHFTF) is proposed. It is composed of three layers with different functions to obtain the temperature control setting model of the RHFTF. In the first layer, the bi-feature Gaussian mixture model clustering (BFGMMC) algorithm of loading plan is proposed to optimize the setting of a limited number of slabs. In the second layer, the type-2 fuzzy rule interpolation (T2FRI) setting method is developed to obtain the optimal setting curve. Meanwhile, an improved KH (Kóczy-Hirota) α-cut distance (IKHCD) algorithm is proposed to get the miss information between any two adjacent interpolation points. In the third layer, knowledge feedforward compensation of rule matrices (KFCRM) algorithm is presented to improve the anti-interference ability of the setting model. The results of the study can demonstrate that the proposed method improves the accuracy of the model and optimizes the control strategy. Furthermore, the experimental results show that the proposed method meets the process technical requirements.