Rolling Temperature Research Articles

Multi-objective optimization of the heating oil circuit inside the calendering roller for the lithium battery pole piece

The heating oil circuit plays an essential role in the heating calendering roller for the lithium battery pole piece. To achieve the optimization of the heating oil circuit, a fluid-thermal-structural coupling method and a multi-objective optimization procedure are proposed to obtain the optimal solution. A fluid–thermal–structural coupling flowchart based on the numerical modeling for the calendering roller temperature distribution is created to automate the analysis processes in the optimization iteration. In the multi-objective optimization procedure, an integrated optimization framework is established by the prebuilt CAD module and the FEM module in the commercial software. Then, the improved NSGA-II algorithm is selected to execute the optimization loop. The methodology was successfully implemented in a redesigned case of a lithium battery rolling equipment company in China. After redesigning the heating oil circuit inside a calendering roller, both the maximum surface temperature non-uniformity and the maximum surface radial thermal deformation of the roller are reduced remarkably by 29.8% and 13.2%, respectively. The results indicate that the proposed method is feasible and makes designing the heating oil circuit easier. The case illustrates that this method can be extended to practical cases of heating oil circuit design for the lithium battery calendering roller.

Suppressing Friction-Induced Stick-Slip Vibration and Noise of Zinc-Coated Steel through Temper Rolling.

The stick-slip phenomenon as a prevalent friction instability poses significant challenges to industry, including frictional vibration, reduced precision, and noise generation. The interfacial interactions between asperities on the surface of materials are critical in influencing stick-slip behavior. This study focused on modifying the asperities on the surface of zinc-coated steel through temper rolling as a new approach to suppress friction-induced stick-slip vibration and noise. It was revealed that temper rolling effectively suppressed the stick-slip behavior when the deformation of zinc-coated steel exceeded 2.3%. The proposed mechanism suggested that the temper rolling reduced surface asperity density, resulting in diminished potential energy fluctuations and a subsequent decrease in the stick-slip amplitude (the difference between the static and kinetic friction coefficients). In situ observation using the digital image correlation (DIC) technique demonstrated that the decrease in the stick-slip amplitude affected the motion state of the friction pair, effectively suppressing the stick-slip vibration and noise generation. These findings highlight the potential of temper rolling as an effective strategy for tailoring the surface topography to suppress the stick-slip phenomenon along with its related vibration and noise.

Distributed H∞$H_\infty$ control for roller kiln temperature based on adaptive dynamic programming

Distributed H∞$H_\infty$ control for roller kiln temperature based on adaptive dynamic programming

Permanent Deformation of Thermoplastic Polyurethane in the Solid‐State Rolling Process

The findings suggest that rolling is a potentially effective technique for commercial applications in industries requiring high‐performance polymer films. The solid‐state rolling process is well‐established for semicrystalline and amorphous polymers, but its application to segmented, two‐phase polymers like thermoplastic polyurethane (TPU) which features physically cross‐linked systems and excellent physical and mechanical properties, remains underexplored. This study aims to investigate the rolling of TPU under various conditions to address viscous relaxation and achieve maximum thickness reduction, producing thin sheets. The rolling characteristics were assessed by measuring the thickness changes of rolled specimens of two TPUs with different hard phase fractions, alongside thermoset polyurethane (PUR) with chemical cross‐linking for comparative analysis. The results showed that the TPUs exhibited little plastic deformation at room temperature. The cold rolling test, conducted at a rolling speed of 0.5 m min−1 with a nominal reduction of 85%, indicated that the permanent reduction ratio was less than 35% for both TPUs. However, when the rolling speed was increased to 3 m min−1, the permanent reduction ratio increased to 67% and 60% for TPU ShA90 and TPU ShA85, respectively. This result indicates that at high rolling speeds, the thermal condition tends to change from isotherm to adiabatic in the rolling test. The maximum reduction ratio of 70% was achieved at a nominal reduction of 85% for TPU ShA90 at higher rolling temperatures and speeds.

Effect of thermal-kinetic conditions of austenite transformation on the structural-phase state of low-carbon steel sheets

The structure and mechanical properties of rolled sheets with a thickness of 40 mm made of lowcarbon low-alloyed steel after thermomechanical treatment of different modes are investigated. The structural factors that affect obtaining high mechanical properties are established. It is shown that a complex treatment including quenching from the rolling temperature and high-temperature tempering with a subsequent additional cycle of quenching and tempering leads to formation of rolled sheet uniform over the cross section with a fragmented bainite structure with disperse niobium carbides and carbides of cementite type. Such structure provides a yield strength of no less than 630 MPa in combination with high values of the impact energy at negative temperatures and a level of plasticity of δ ≈ 20%.

Capabilities of asymmetric rolling of single-layer and laminated materials made from aluminum and its alloys

Asymmetric rolling of aluminum alloys is one of the methods for improving their mechanical and performance characteristics. Kinematic asymmetry during rolling is achieved by varying the roll speed ratios (V1 /V2). It is believed that when V1 /V2 > 3, the process of asymmetric rolling, by combining significant compression and shear deformations, approximates the processes of severe plastic deformation. It has been found that the majority of studies are based on data obtained within a limited roll speed ratio range, V1 /V2 < 2, in asymmetric rolling. This article examines the effects observed at V1 /V2 = 1÷7.7. The implementation of this condition became possible thanks to a unique scientific facility – the 400 laboratory-industrial asymmetric rolling mill at the Zhilyaev laboratory “Mechanics of Gradient Nanomaterials” at Nosov Magnitogorsk State Technical University Experiments were conducted on asymmetric thin-sheet rolling of aluminum alloys 2024, 5083, and 6061, as well as accumulative roll bonding to produce laminated sheet aluminum composites 5083/2024, 5083/1070, and 6061/5083. The disadvantages of asymmetric rolling compared to symmetric rolling were identified: sample failure was observed at single relative reductions of 37 % for layered sheet aluminum composites (5083/2024) and 40 % for thin-sheet aluminum alloys (6061). The nuances of material preparation for processing were described, including the necessity of cleaning and degreasing the alloy surfaces before bonding into a composite. The rolling temperature regimes were selected, determining cold asymmetric thin-sheet rolling (room temperature processing) and warm asymmetric accumulative roll bonding (heating of the workpieces in the furnace before rolling at 320–350 °C). A reduction in rolling force (by a minimum of 1.3 times), the ability to vary hardness (including an increase by a minimum of 30 %), and technological plasticity with changes in the roll speed ratios within the range of 2 to 7.7 were demonstrated. Options were proposed for reducing the processing cycles of aluminum alloys without compromising the quality of the finished product by reducing the number of rolling passes and annealing steps in the standard process scheme.

Исследование распределения нормальных контактных напряжений в очагах деформации при горячей прокатке полос из конструкционных низколегированных сталей для повышения стойкости рабочих валков

Introduction. During the operation of the working rolls of the finishing groups of continuous wide-strip hot rolling mills, normal contact stresses have a decisive influence on its resistance and strength, especially when rolling a range of low-alloy structural steels with a minimum thickness range of 5.5–2.0 mm, which does not correspond to the passport characteristics of such mills. The subject of the study. Previously performed studies of the stress-strain state of the rolled strip in the deformation zones make it possible to estimate the level of normal contact stresses acting on the working rolls during hot rolling of strips of low-carbon steels. The paper discusses the results of the study of the stressed state of strips of low-alloy structural steels in contact with rolls, taking into account the features of the chemical composition of the metal and changes in its elastic properties during deformation at hot rolling temperatures. The results obtained are applicable to the evaluation of the contact strength of the finishing rolls of the rolling mill. The purpose of the work is to investigate the distribution of normal contact stresses in the deformation zones during hot rolling of strips of low-alloy structural steels to ensure high resistance of the working rolls. Material and methods. The study is based on the elastic-plastic model and equations for calculating normal contact stresses for each section of the deformation zone. The specificity of variation of Young's modulus (modulus of elasticity) of low-alloyed structural steels in accordance with certain hot rolling temperatures is studied in detail, and the contact strength of high-chromium cast iron work rolls is evaluated. Results and discussion. A reliable regression equation is obtained for determining the values of the Young’s modulus of the rolled strip as a function of changing hot rolling temperatures. The results of a numerical experiment are presented in the form of calculating the maximum normal contact stresses using the elastic-plastic model of the deformation zone and assessing the contact strength of the work rolls based on actual rolling conditions on an operating mill. New improved technological modes of hot rolling of low-alloy structural steels (0.1 C-Cr-Si-Ni-Cu, 0.18 C-Cr-Mn-Ti and 0.14 C-2 Mn-N-V) are proposed, which make it possible to reduce the maximum contact stresses and increase the resistance of the working rolls.

Deciphering the effects of rolling temperature on the texture development and formability of W1 and WZ10 magnesium alloy

For an improvement in the properties of semi-finished products, the detailed knowledge of the influence of the manufacturing process on the microstructure and texture evolution of the flat products is required. Rolling of sheets has been conducted at various temperatures to study the difference between the two alloys W1 (Mg1Y) and WZ10 (Mg1Y0.5Zn) in terms of microstructure- texture development and their formability at room temperature. For WZ10 it can be shown, that the formability strongly depends on the rolling temperature which can be increased after additional heat treatment. A strongly deformed microstructure is a prerequisite for the as-rolled condition to form the quadrupole type of texture during subsequent annealing, which stands for high formability. Whereas W1 behaves differently and shows the highest formability in the as rolled condition. The research reveals that the high proportion of shear bands, or the internal energy already contained in the material, is responsible for the different deformation behavior of the rolled sheet, leading to a higher activity of non-basal slip systems.

Optimization of the Thickness Ratio and Roll-Bonding Parameters of Bimetallic Ti/Al Rod for Bending-Dominated Negative Thermal Expansion Metamaterials.

Roll-bonding has rarely been applied to prepare rods for negative thermal expansion metamaterials (NTEMs). Parameters for quantitatively assessing the isotropy and cyclic thermal stability of the thermal expansion coefficient α of NTEMs are lacking. Here, the Ti-to-Al thickness ratio in bimetallic rods for "cross-shaped" node bending-dominated NTEMs was optimized using a general model proposed in the literature. The finite element method was used to determine the optimal initial thickness ratio of the billet, as well as the reduction ratio and rolling temperature. NTEMs were prepared with roll-bonded Ti/Al rods and Ti nodes. A relatively high thermal expansion coefficient was obtained when the thickness ratio of the 7075 Al alloy of the rods was in the range of 0.56-0.60. The optimized roll-bonding process to meet this thickness ratio was as follows: a rolling temperature of 400 °C, a reduction ratio of 50%, and TA1 Ti and 7075 Al billet thicknesses of 0.5 mm and 1.5 mm, respectively. The isotropy and cyclic thermal stability ratios were proposed to quantitatively assess the isotropy and cyclic thermal stability of the NTEMs. These results help to expand the preparation and evaluation methods for NTEMs.

Heterogeneous Fe-Mn-Al-C lightweight steel breaking the strength-ductility trade-off via high-temperature warm rolling process

In this study, a lightweight heterogeneous Fe-6Mn-4.1Al-0.41C-0.62Si-0.2 V (wt%) steel with the synergy of high tensile strength and ductility was achieved by warm-rolling at 850 °C with a 93 % thickness reduction, namely, an ultimate tensile strength of 1.18 GPa, a total elongation of 35.4 %, and the product of strength and elongation (PSE) of 41.9 GPa%. The microstructure of the investigated steel consists of δ-ferrite (δ-F), retained austenite (RA), inter-critical ferrite (IF) and Fe3C precipitates. The moderate stability of RA, induced by its different morphologies (i.e., lath, block shape), provides a discontinuous and local phase transformation-induced plasticity (TRIP) effect that contributes to the excellent work hardening ability. Meanwhile, the isomeric hetero deformation induced (HDI) strengthening between RA and δ-F, and between RA and IF, further enhances the investigated steel's high strength and ductility. In addition, our results indicate that increasing the rolling temperature results in the increment of RA, while increasing the rolling reduction (i.e., 5 % at 800 °C) has a limited effect on the formation of RA.

Review of Electrical Steels with their Properties and Recent Trends for Improvement

Objectives: This review study provides a thorough analysis of the magnetic behavior and characteristics of electrical steels, including established and novel materials (3%wt Silicon). Methods: We investigate how composition, microstructure, and processing methods affect the magnetic performance of these steels as well as the basic principles guiding their behavior. Thermomechanical processing can be observed for its impact on the material’s microstructure and magnetic properties. This review discusses testing over samples for conventional processes for different % of cold worked or strain hardening and annealing at higher temperatures i.e., 1200°C. For uncertainties regarding the impact of impurities or inclusions on their magnetic properties, the study was carried out to know the effect of cerium addition on the material’s magnetic properties of the material. Findings: It was observed that rolling temperature has significant effect over magnetic properties of the material. A notable improvement in the magnetic permeability of the material and its critical performance metric for soft magnetic materials is indicated by the increase in “Gamma max”. Similarly, the effects of compressive stresses, doping effect, grain size, annealing, and other manufacturing processes were studied, and observed their impact on magnetic properties. This review discusses the literature on future scope with the latest trends. This helps clarify the trade-offs associated with maximizing electrical steels for certain uses. Novelty: This study presents a novel approach towards electrical steel and its magnetic properties by incorporating different alloying elements and optimizing rolling & annealing parameters. A key innovation is the application of machine learning and neural network to predict and optimize material behavior, core loss and provide methods to improve magnetic properties of electrical steels. Significance: Electrical steels are crucial in transformers and electric motors, enhancing efficiency by minimizing energy losses and improving magnetic performance. This can be achieved by changing manufacturing parameters and operating conditions with the help of latest trends. Keywords: Electrical steel, Magnetic properties, Machine learning, Composition, Microstructure, Core loss

Influence of Hot Rolling on Microstructure, Corrosion and Mechanical Properties of Mg–Zn–Mn–Ca Alloy

The effect of hot rolling on the microstructure, mechanical, and corrosion properties of the magnesium alloy 96 wt% Mg–2.3 wt% Zn–0.7 wt% Ca–1 wt% Mn was studied. After heat treatment, the original plates of an as-cast alloy were rolled from a 7 mm thickness to a 0.2 mm thickness at two temperatures—300 or 400 °C. It has been established that increasing the rolling temperature from 300 to 400 °C increases the fraction of recrystallized grains in the microstructure and after rolling at 400 °C, the microstructure is fully recrystallized. The best strength–ductility balance of the alloy was obtained after rolling at 300 °C, with a high total percentage reduction of 93–97%: the yield stress, the ultimate tensile strength, and the elongation averaged at 285 MPa, 310 MPa, and 5%, respectively. The alloy after rolling, annealed at 400 °C, shows improved ductility but lower strength: the yield stress, the ultimate tensile strength, and the elongation were 200 MPa, 260 MPa, and 17%, respectively. The strong dependence of corrosion resistance on respect to rolling direction is observed, which can be reduced after heat treatment. The as-rolled alloy and the heat-treated alloy had low corrosion rates in Hanks’ solution of 0.54 and 0.19 mm/year, respectively.

Effect of Rolling Process Parameters on Transverse Cracks on the Surface of Q345 Steel

This article examines the evolutionary behavior of transverse surface cracks in Q345 steel during the hot‐rolling process under various rolling conditions. “V”‐shaped cracks are prefabricated on the billet surface for laboratory hot‐rolling tests, and a corresponding rolling model is developed to validate its accuracy. The slab rolling model is established based on actual onsite rolling process parameters. The aim is to analyze the effects of different rolling conditions on the surface crack morphology and aspect ratio. The results indicate that variations in roll diameter (1400, 1300, and 1200 mm) influence crack propagation, with cracks unfolding earlier when the roll diameter is 1400 mm. At varying initial rolling temperatures (1300, 1200, and 1100 °C), cracks begin to unfold earlier at the highest temperature of 1300 °C. When examining different friction coefficients (0.4, 0.5, and 0.6), cracks unfold earlier at the highest coefficient of 0.6. Similarly, at different rolling speeds (3, 4, and 5 m s−1), cracks unfolded earlier at the highest speed of 5 m s−1. Analysis of changes in crack depth and aspect ratio during rolling shows that the initial few passes have a greater influence on crack depth and unfolding. In the later stages of rolling, cracks continue to unfold, though the depth shows minimal variation, and the aspect ratio tends to approach zero.

Hot deformation behavior and hot rolled properties of Gd-rich 316 L austenitic stainless steel neutron shielding material for spent nuclear fuel storage and transportation

Gd-rich austenitic stainless steel as a low-cost neutron shielding structural-functional integrated material is considered the most promising material to replace boron neutron shielding materials. However, as-cast Gd-rich austenitic stainless steel neutron shielding materials are affected by high hardness, low melting point, net-like, brittle intermetallic compound (Fe,Ni,Cr)3Gd, and its hot workability and mechanical properties are very poor. In this paper, Gd-rich 316 L austenitic stainless steel neutron shielding material hot deformation behavior was revealed, and the constitutive equation and hot processing maps were established and verified. On this basis, the effects of hot rolling on material microstructure and properties were studied, mainly discussing the effects of rolling temperature and subsequent solution treatment on the microstructure, recrystallization, mechanical properties, and neutron shielding properties. Studies have shown that Gd-rich 316 L austenitic stainless steel neutron shielding material has good hot workability at deformation temperatures of 950 ∼ 1050 °C and strain rates of 0.01 ∼ 0.1 s−1. Compared with before hot rolling, the strength, elongation and neutron shielding properties of 1050 °C hot-rolled 316 L-2.5wt%Gd neutron shielding material are increased by 1.79 times, 1.96 times and 1.31 times, respectively. After solution treatment at 1100 °C × 60 min, the elongation further increased to 39.53 %, which was 4.32 times than before hot rolling. This study provides valuable insights for high Gd content austenitic stainless steel neutron shielding materials thermo-mechanical processing and improving the strength and plasticity.

Effect of deformation temperature on the microstructure and texture evolution of Ti-6Al-4Zr-2Mo-6V alloy

In this work, the effect of deformation temperature on the microstructure, texture, and tensile properties of a Ti-6Al-4Zr-2Mo-6V (wt. %) alloy was systematically investigated. The whole samples were composed of an equiaxed α phase, a strip α phase, and a β transformed microstructure. The recrystallization area fraction increased with the increase of deformation temperature. The orientation distribution of a retained β phase was {001}β⟨110⟩β texture regardless of deformation temperature. The textured microstructure of an α phase was {12¯10}α⟨101¯0⟩α under the 810 and 840 °C condition. Additional {112¯0}α⟨0001⟩α texture was observed as the rolling temperature increased to 870 °C. The yield strength and the tensile strength of a rolling direction were lower than that of a transverse direction. The yield strength of a rolling direction and a transverse direction were both above 990 MPa when the deformation temperature was 840 °C. In summary, the present study provided theoretical guidance for the high strength titanium alloy applied for the marine engineering field.

Investigation of an Innovative Roll-to-Plate (R2P) Hot-Embossing Process for Microstructure Arrays of Infrared Glass.

The roller-to-plate (R2P) hot-embossing process is an effective, low-cost method for producing high-quality micro-/nano-optical components. In the field of night vision applications, the fabrication of chalcogenide glass microstructures is emerging as a promising alternative to traditional infrared glass. This trend is driven by the potential of chalcogenide glass to surpass conventional materials in terms of performance. However, the development of R2P hot embossing faces challenges, such as the high cost of curved mold manufacturing, the reliance on roll-to-roll processes for nano hot embossing, the limitations of plastic materials, and the unclear viscoelastic properties of infrared glass. In this study, a novel R2P hot-embossing process was developed to fabricate flat chalcogenide glass structures. The key parameters, such as roller temperature, speed, and embossing pressure, were investigated to understand their impact on the glass-filling performance. The deformation mechanism of the glass microstructures was also analyzed. The experimental results show that the R2P hot-embossing method offers excellent reproducibility, achieving a maximum filling rate of 96% and an average roughness deviation of 8.36 nm. The increase in the roller temperature and embossing force increased the filling height of the glass microstructure arrays, while an increase in the roller speed decreased the filling height. Different embossing methods, including variations in speed, temperature, and force, are summarized to analyze the structural changes during embossing. This study provides a foundation and a basis for future research on the roller-to-plate hot embossing process.

Evaluation of filtration characteristics of bentonite-free water-based mud utilizing carboxymethylated tapioca starch

Optimizing filtercake thickness is crucial to prevent fluid losses during well drilling and avoid borehole instability and complex operations. This research develops a non-damaging water-based mud with chemically modified carboxymethylated tapioca starch and investigating its filtration control properties. Fluid loss volume and filtercake thickness were determined both at API, HPHT (500 psi and 212 °F), and hot roll temperatures (200, 230, and 260 °F) using filterpress. The mud’s properties were compared to the existing fluid loss control agent-PAC-LV. The results indicated that optimum samples exhibited 17.33% reduction before hot rolling and 46.76%, 31.67%, and 70.51% reductions at 200, 230, and 260 °F, respectively. At ambient and after hot rolling at 200 °F and 230 °F, 8 ppb CMTS concentration achieved the lowest cake thickness. At 260 °F, the 10-ppb concentration had the lowest thickness. Optimized values resulted in permeability reductions of 49.73%, 58.74%, 57.04%, and 60.10% for BHR and AHR at 200, 230, and 260 °F, respectively. Morphological study showed the fingerlike structure effectively bound free water and plugged channels, reducing permeability and fluid loss volume.

Precipitation behavior of Al2CuLi, Al3Li and Al3Zr in A2060 aluminum-lithium alloys and mechanical behavior of their microinterfaces

The precipitated phase of Al-Li alloy is a major factor determining the properties of Al-Li alloy. Al2CuLi phase(T1 phase), Al3Li phase and Al3Zr phase are all important enhanced precipitated phases. In this paper, the properties of the matrix, the precipitated phase and the interface formed between each phase are calculated. The (111) crystal face of Al, (111) of Al3Li, (111) of Al3Zr, and (210) of Al2CuLi are the surfaces with the lowest surface energy of these phases. Al3Li/Al3Zr has the lowest interfacial energy (0.01961ev), so its thermodynamic stability is the best. The interface with the maximum bonding strength is the interface of Al3Zr/T1, and its adhesion work is 0.61878ev. A2060 aluminum-lithium alloy was thermally insulated at 580 °C for 2h and then hot rolled. After hot rolling, it was cooled to room temperature for cold rolling. Then the samples were treated with solid solution and aging, and different cooling methods were selected to obtain four kinds of samples: non-heat treatment, aging, air cooling and water quenching. It is found that the strength and hardness of Al-Li alloy are determined by the grain thickness of precipitated phase, and the ductility and hardness of Al-Li alloy are determined by the number of precipitated phase and the degree of dislocation density.

Effect of hot rolling process parameters on surface wear of descaling rolls

PurposeThe purpose of this study is to explain the effect of slab and roll initial temperatures on the wear characteristics of the surface of hot roll descaling rolls.Design/methodology/approachThe UMESHMOTION subroutine and the Arbitrary Lagrangian-Eulerian adaptive mesh technique are used to investigate the wear profile of the descale roll surface and to evaluate the effect of the slab and roll’s initial temperature on the wear depth.FindingsWear is more pronounced at the edges of the roll-slab contact area and less severe in the roll-body’s central region. A rise in the initial slab temperature from 1,337 K to 1,429 K results in a 67% rise in maximum wear depth and 52% in frictional stress. The peak wear region progressively shifted toward the center of the roll body. A rise in the initial roll temperature from 308.15 K to 673.15 K caused a 46% reduction in maximum wear depth and 73% in frictional stress. The location of the peak wear region remained primarily unchanged.Originality/valueThis study used the UMESHMOTIONI subroutine and the Arbitrary Lagrangian-Eulerian adaptive mesh technique in ABAQUS® to evaluate the quantitative correlation between the wear depth of the descaling roll surfaces and the initial temperatures of the slab and rolls. This study offers valuable insights into improving the wear of descaling roll surfaces.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0231/

The effect of non-uniform skelp temperature on X70 steel coil cooling

This study explored the effect of varying steel skelp temperature (500 °C–600 °C) on the subsequent temperature-time ( T- t) profile during and after coiling of low C (0.05 wt. %) X70 microalloyed steels. Three industrially produced steel coils with similar rough rolling temperatures (∼1050 °C) and finish rolling temperatures (∼850 °C) but different coiling temperatures (500 °C–600 °C) and different skelp thicknesses (19 mm and 25 mm) were studied. The surface temperature of each coil was measured using an infrared video camera. A three-dimensional heat transfer model was developed to predict the T- t profiles. A lower (∼60 °C) initial skelp temperature near the head and tail of the skelp led to a reduced coil temperature. A higher (∼50 °C) temperature near the head and tail region of the skelp resulted in a more uniform coil temperature (a difference of ∼10 °C instead of ∼50 °C).