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We performed a machine learning-aided analysis of the rolling and recrystallization textures in pure iron with different cold reduction ratios and cold-rolling directions. Five types of specimens with different cold reduction ratios and cold-rolling directions were prepared. The effect of two-way cold-rolling on the rolling texture was small at cold reduction ratios different from 60%. The cold reduction ratio in each stage hardly affected the texture evolution during cold-rolling and subsequent short-term annealing. In the case of long-term annealing, although abnormal grain growth occurred, the crystal orientation of the grains varied. Moreover, the direction of cold-rolling in each stage also hardly affected the texture evolution during cold-rolling and subsequent short-term annealing. During long-term annealing, sheets with the same cold-rolling direction in the as-received state and in the first stage showed the texture evolution of conventional one-way cold-rolled pure iron. Additionally, we conducted a machine learning-aided analysis of rolling and recrystallization textures. Using cold-rolling and annealing conditions as the input data and the degree of Goss orientation development as the output data, we constructed high-accuracy regression models using artificial neural networks and XGBoost. We also revealed that the annealing temperature is the dominant factor in the nucleation of Goss grains.

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In this paper, a Cr coating was prepared by induction heating and pack-cementation chromizing on AISI 304 austenitic stainless steel. Then, the cold-rolling deformation and annealing treatment were introduced to refine the coarse matrix grains caused by pack-chromizing and improve the overall performance of 304 austenitic stainless steel. The phase composition, element distribution, and microstructure of the coating were carefully characterized. The microhardness, wear resistance, and corrosion resistance of the coating were tested. The results show that the Cr coating with a thickness of 100 µm is mainly composed of a (Cr,Fe)23C6, (Cr,Fe)7C3, and α-Fe-Cr solid solution. After the cold-rolling deformation and subsequent annealing treatment, the grains are significantly refined and the Cr coating is divided into two layers, consisting of carbon-chromium compounds such as Cr23C6, Cr7C3, Cr2C, and Cr3C2 in the surface layer and a Fe-Cr solid solution in the subsurface layer. The cold-rolling deformation and annealing treatment significantly improved the microhardness and wear resistance of the coated sample, and the corrosion resistance was also better than that of the uncoated sample.

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Metal implants require an elastic modulus close to cortical bone (<30 GPa) to avoid stress shielding and ensure adequate load-bearing strength. The metastable ß-type Ti-25Nb-8Sn alloy has a low elastic modulus (52 GPa), but its yield strength (<500 MPa) needs enhancement. This study enhances Ti-25Nb-8Sn's elastic admissible strain through cold rolling and aging heat treatments, investigating the microstructure's impact on mechanical and corrosion properties. The results show that lower-temperature aging (<450 °C) leads to ω-phase precipitation, yielding a 300% increase in yield strength (>1900 MPa). However, this also increases the elastic modulus (~80 GPa), limiting the deformation ability. Higher-temperature aging (>500 °C) eliminates the ω phase, transforming it into α precipitates, resulting in a lower elastic modulus (~65 GPa) and improved deformation ability, with substantial yield strength (>1000 MPa). In summary, the optimal process conditions are determined as 90% cold rolling followed by aging treatment at 550 °C. Under these conditions, Ti-25Nb-8Sn achieves the most suitable yield strength (1207 MPa) and high corrosion resistance, retaining a relatively low elastic modulus (64.7 GPa) and high elastic admissible strain (1.93%). This positions it as an ideal material for biomedical implants.

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This study investigates the effectiveness of combined thermal and athermal stimuli in mitigating the extremely high-density nature of dislocation networks in the form of low-angle grain boundaries in FeCrAl alloy. Electron wind force, generated from very low duty cycle and high current density pulses, was used as the athermal stimulus. The electron wind force stimulus alone was unable to remove the residual stress (80% low-angle grain boundaries) due to cold rolling to 25% thickness reduction. When the duty cycle was increased to allow average temperature of 100 °C, the specimen could be effectively annealed in 1 min at a current density of 3300 A/mm2. In comparison, conventional thermal annealing requires at least 750 °C and 1.5 h. For specimens with 50% thickness reduction (85% low-angle grain boundaries), the electron wind force was again unable to anneal the defects even at 3300 A/mm2 current density and average temperature of 100 °C. Intriguingly, allowing average concurrent temperature of 200 °C eliminated almost all the low-angle grain boundaries at a current density of 700 A/mm2, even lower than that required for the 25% thickness reduced specimens. Comprehensive electron and X-ray diffraction evidence show that alloys with extremely high defect density can be effectively annealed in less than a minute at approximately 200 °C, offering a substantial improvement over conventional high-temperature annealing.

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The microstructure and texture evolution of Cu-Ni-P alloy after cold rolling and annealing at 500 °C was studied by electron backscattering diffraction (EBSD). The equiaxed grain is elongated and the dislocation density increases gradually after cold rolling. The grain boundaries become blurred and the structure becomes banded when the reduction in cold rolling reaches 95%. A typical rolling texture is formed with the increase in deformation amount in cold rolling. The deformation structure gradually disappeared and recrystallized new grains were formed after annealing at 500 °C. The recrystallization nucleation mechanism of Cu-Ni-P alloy at 60% reduction is mainly a bow nucleation mechanism. A shear band begins to form after annealing at 80% reduction. The shear band becomes the preferred nucleation location with the increase in reduction. Most adjacent recrystallized grains growing in the shear band have a twin relationship.

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The microstructure evolution associated with the cold forming sequence of an Fe-14Cr-1W-0.3Ti-0.3Y2O3 grade ferritic stainless steel strengthened by dispersion of nano oxides (ODS) was investigated. The material, initially hot extruded at 1100 °C and then shaped into cladding tube geometry via HPTR cold pilgering, shows a high microstructure stability that affects stress release heat treatment efficiency. Each step of the process was analyzed to better understand the microstructure stability of the material. Despite high levels of stored energy, heat treatments, up to 1350 °C, do not allow for recrystallization of the material. The Vickers hardness shows significant variations along the manufacturing steps. Thanks to a combination of EBSD and X-ray diffraction measurements, this study gives a new insight into the contribution of statistically stored dislocation (SSD) recovery on the hardness evolution during an ODS steel cold forming sequence. SSD density, close to 4.1015 m-2 after cold rolling, drops by only an order of magnitude during heat treatment, while geometrically necessary dislocation (GND) density, close to 1.1015 m-2, remains stable. Hardness decrease during heat treatments appears to be controlled only by the evolution of SSD.

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Over the years, various processing techniques have been explored to synthesize three-dimensional graphene (3DG) composites with tunable properties for advanced applications. In this work, we have demonstrated a new procedure to join a 3D graphene sheet (3DGS) synthesized by chemical vapor deposition (CVD) with a commercially available carbon veil (CV) via cold rolling to create 3DGS-CV composites. Characterization techniques such as scanning electron microscopy (SEM), Raman mapping, X-ray diffraction (XRD), electrical resistance, tensile strength, and Seebeck coefficient measurements were performed to understand various properties of the 3DGS-CV composite. Extrusion of 3DGS into the pores of CV with multiple microinterfaces between 3DGS and the graphitic fibers of CV was observed, which was facilitated by cold rolling. The extruded 3D graphene revealed pristine-like behavior with no change in the shape of the Raman 2D peak and Seebeck coefficient. Thermoelectric (TE) power generation and photothermoelectric responses have been demonstrated with in-plane TE devices of various designs made of p-type 3DGS and n-type CV couples yielding a Seebeck coefficient of 32.5 µV K-1. Unlike various TE materials, 3DGS, CV, and the 3DGS-CV composite were very stable at high relative humidity. The 3DGS-CV composite revealed a thin, flexible profile, good moisture and thermal stability, and scalability for fabrication. These qualities allowed it to be successfully tested for temperature monitoring of a Li-ion battery during charging cycles and for large-area temperature mapping.

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Austenitic stainless steel has high toughness and plasticity; however, it tends to exhibit low yield strength, which severely limits the widespread application of this steel. It can be strengthened by cold working; however, this will cause many defects in the structure. Therefore, annealing treatment must be carried out before use. In this paper, the effects of annealing treatment at different temperatures and times on the microstructure and mechanical properties of cold-rolled 305 stainless steel sheet were studied and the theoretical mechanism was further analyzed to provide better theoretical guidance for production and application. It was found that the microstructure grains obtained by annealing at 850 °C for 30 s were finer and more uniform, and the mechanical properties were also the best, which met the requirements of strong plasticity. Therefore, the rolling and annealing experiments could be carried out again under this annealing condition, and the requirements of the finished product could be finally obtained. At this time, the thickness of the plate was about 0.15 mm, the yield strength was 1238 MPa, and the permeability was below 1.02, which met the production requirements of the metal mask plate.

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Al 6082 aluminum alloy has excellent corrosion resistance, strength, and formability. However, owing to the recrystallization effect of a hot working process, coarse grains form easily in this material, which reduces its strength and service life. The novel continuous casting direct rolling (CCDR) method can prevent the deterioration of this material. Thus, we used CCDR Al 6082 aluminum alloy as the research material in this study. By subjecting a CCDR Al 6082 aluminum alloy to heat treatment (T4 and T6) and cold rolling, the influence of recrystallization effect on its mechanical properties and on impact failure resistance were explored. The results demonstrated that the specimen subjected to T4 heat treatment had a higher elongation and that the specimen subjected to T6 heat treatment had a higher strength. After cold rolling, the hardness and strength of the specimens subjected to different heat treatments (coded T4R4 and T6R4) increased because of the work's hardening effect. Moreover, the elongations of both specimens decreased, but they were higher than the industrial standard (>10%). The strength of specimen T6R4 was higher (up to 400 MPa) than specimen T4R4. Moreover, relative to specimen T4R4, specimen T6R4 had greater tensile and Charpy impact failure toughness.

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The study presented in this paper is focused on the effect of varying the solution treatment duration on both the microstructural and mechanical properties of a cold-deformed by rolling Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt.%) alloy, referred to as TNZTSF. Cold-crucible induction using the levitation synthesis technique, conducted under an argon-controlled atmosphere, was employed to fabricate the TNZTSF alloy. After synthesis, the alloy underwent cold deformation by rolling, reaching a total deformation degree (total applied thickness reduction) of 60%. Subsequently, a solution treatment was conducted at 850 °C, with varying treatment durations ranging from 2 to 30 min in 2 min increments. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were utilized for the structural analysis, while the mechanical properties were assessed using both tensile and hardness testing. The findings indicate that (i) in both the cold-deformed-by-rolling and solution-treated states, the TNZTSF alloy exhibits a microstructure consisting of a single ß-Ti phase; (ii) in the solution-treated state, the microstructure reveals a rise in the average grain size and a decline in the internal average microstrain as the duration of the solution treatment increases; and (iii) owing to the ß-phase stability, a favorable mix of elevated strength and considerable ductility properties can be achieved.

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Titanium-rich metastable medium-entropy alloys, designed for low elastic moduli, sacrifice strength. However, enhancing their mechanical strength is crucial for bio-implant applications. This study aims to enhance the mechanical properties and corrosion resistance of a metastable Ti80-Nb10-Mo5-Sn5 medium-entropy alloy using various treatments, including cold rolling (at 50% and 75% reduction) and precipitation hardening (at room temperature, 150 °C, 350 °C, 550 °C, and 750 °C). The results showed that the alloy underwent a stress-induced martensitic transformation during the rolling process. Notably, the α phase was precipitated in the ß grain boundaries after 30 days of precipitation hardening at room temperature. The yield strengths of the alloy increased by 51% and 281.9% after room-temperature precipitation and 75% cold rolling, respectively. In potentiodynamic corrosion tests conducted in phosphate-buffered saline solution, the pitting potentials of the alloy treated using various conditions were higher than 1.8 V, and no pitting holes were observed on the surface of the alloys. The surface oxide layer of the alloy was primarily composed of TiO2, Nb2O5, MoO3, and SnO2, contributing to the alloy's exceptional corrosion and pitting resistance. The 75% rolled Ti80-Nb10-Mo5-Sn5 demonstrates exceptional mechanical properties and high corrosion resistance, positioning it as a promising bio-implant candidate.

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This paper introduces a novel method for enhancing fault classification and diagnosis in dynamic nonlinear processes. The method focuses on dynamic feature extraction within multivariate time series data and utilizes dynamic reconstruction errors to augment the feature set. A fault classification procedure is then developed, using the weighted maximum scatter difference (WMSD) dimensionality reduction criterion and quadratic discriminant analysis (QDA) classifier. This method addresses the challenge of high-dimensional, sample-limited fault classification, offering early diagnosis capabilities for online samples with smaller amplitudes than the training set. Validation is conducted using a cold rolling mill simulation model, with performance compared to classical methods like linear discriminant analysis (LDA) and kernel Fisher discriminant analysis (KFD). The results demonstrate the superiority of the proposed method for reliable industrial process monitoring and fault diagnosis.

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In this study, the evolutions of Cube and {115}<161> orientations of a cold-rolled ultra-thin non-oriented silicon steel were investigated using a combination of experimental investigation and the crystal plasticity finite element method (CPFEM). The results show that Cube orientations remain relatively stable when their initial deviation angles from the ideal Cube orientation are less than 12°, even after a 60% cold rolling reduction. However, larger deviations occur due to higher strain near grain boundaries. Furthermore, the {115}<161> orientations, with an initial deviation of ~18° from the ideal Cube orientation, become separated into different orientation regions during cold rolling. Some regions gradually approach the ideal Cube orientation as cold rolling progresses and reach ~12.5° deviation from the ideal Cube at a 40% reduction. This study demonstrates good agreement between simulation and experimental results, highlights the micro-deformation mechanisms during rolling, and offers insights for optimizing the ultra-thin strip rolling process.

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This study presents a novel approach to producing superficial micro- and nanostructures using a cold rolling process with rough rolls, followed by low-temperature annealing. The proposed technique attempts to recreate the superficial deformation occurring in the sandblasting process. It allows for the generation of an inhomogeneous network, or tangle, of high-deformation zones on the material's surface that act as nucleation centers during the subsequent annealing process. However, the proposed method has a significant advantage over sandblasting: it is a continuous process with high productivity. An austenitic stainless-steel sheet, previously normalized, was used as the raw material. The samples were cold rolled using rough rolls (rhombic-based pyramids of 2.08 mm, 1.04 mm, and 1.5 mm in length, width, and height, respectively) and annealed at temperatures between 200 °C and 400 °C for one hour. An optical and electronic microstructure analysis showed the presence of small, heterogeneously distributed surface grains of 200-300 nm in diameter. Finite element analysis revealed significant deformation that was inhomogeneous and likely responsible for the uneven distribution of the recrystallized grains. Additionally, surface nanohardness results showed a 20% increase with respect to the central zone of the material. Finally, wear tests of the treated samples showed lower wear than samples rolled with conventional rolls.

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Quenching and partitioning (Q&P) steel has garnered attention as a promising third-generation automotive steel. While the conventional production (CP) method for Q&P steel involves a significant cumulative cold rolling reduction rate (CRRR) of 60-70%, the thin slab casting and rolling (TSCR) process has emerged as a potential alternative to reduce or eliminate the need for cold rolling, characterized with a streamline production chain, high-energy efficiency, mitigated CO2 emission and economical cost. However, the effect of the CRRR on the microstructure and properties of Q&P steel with an initial ferrite-pearlite microstructure has been overlooked, preventing the extensive application of TSCR in producing Q&P steel. In this work, investigations involving different degrees of CRRRs reveal a direct relationship between increased reduction and decreased yield strength and plasticity. Notably, changes in the microstructure were observed, including reduced size and proportion of martensite blocks, increased ferrite proportion and decreased retained austenite content. The decrease in yield strength was primarily attributed to the increased proportion of the softer ferrite phase, while the reduction in plasticity was primarily linked to the decrease in retained austenite content. This study provides valuable insights for optimizing the TSCR process of Q&P steel, facilitating its wider adoption in the automotive sector.

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Aluminium alloy 7005 is widely used for structural purposes because of its attractive properties such as good weldability and age-hardening capability. However, since the workability of this alloy falls after a short period of natural aging, the application of cold rolling for the production of strain-hardened sheets of this alloy is a challenge. Two solutions proposed to overcome this challenge are as follows: (a) immediate rolling of the alloy after solution treatment and (b) rolling of the alloy after artificial aging. However, there is no comprehensive study comparing the effect of pre-rolling aging treatments on the evolutions of microstructure and texture of the alloy through heavy cold rolling. This subject is the aim of the present study. For this purpose, different pieces of the alloy are subjected to three different heat treatments before rolling, and afterward, they are rolled to obtain a thickness reduction of 80%. Scanning electron microscopy with electron backscattered diffraction observations are applied to study the evolutions of the microstructure and the texture of the alloy. Results show that the progression of pre-rolling aging decreases the incidence of micro-scaled shear bands by rolling. In addition, the rolling texture intensity decreases with the advancement of pre-rolling aging. Mechanisms responsible for this effect are discussed.

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In the cold rolling process, edge cracks, particularly those near the welded zone, can inadvertently lead to strip rupture. This study employed the extended finite element method (XFEM) to analyze the crack propagation behavior in welded strip steel during cold rolling. Various tests such as the tensile test, essential work of fracture (EWF) test, spherical indentation method, and elastoplastic finite element simulations were conducted to determine the maximum principal stress and fracture energy utilized in XFEM for the base metal and weld metal, respectively. A continuous cold rolling model was established to investigate the crack propagation behaviors in the base metal, weld metal, and the interface between the base and weld metal. In the continuous rolling process, the crack propagation and expansion speed in the base metal are much larger than that of the weld zone. In addition, the base metal at the back end of the rolled piece is more prone to fracture than the base metal at the front end.

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Rolling treatments have been identified as a promising fabrication and deformation processing technique for graphene/metal composites with high performance. However, it is still a challenge to choose appropriate rolling parameters to achieve high strength, ductility and electrical conductivity of the composite simultaneously. In this study, graphene/Cu composites were prepared with an in situ growth method and rolling treatment. The effects of rolling deformation and temperature on the microstructural evolution of graphene and Cu grains, interface bonding between graphene and the matrix, mechanical and electrical properties were systemically investigated. The cold-rolled composite with 85% deformation displayed a maximum ultimate strength of 548 MPa, a high elongation of 8.8% and a good electrical conductivity of 86.2% IACS. This is attributed to oriented graphene arrangement and matrix grain refinement. Our research provides a comprehensive understanding for the rolling behavior of graphene/Cu composites, and can promote the development of graphene-based composites with high performance.

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Dewatering is critical to oily cold rolling mill (CRM) sludge treatment. Therefore, finding an efficient, energy-saving, and applicable dewatering technology for oily CRM sludge is still urgent. This study investigated the performance of quicklime as a conditioning agent for oily CRM sludge conditioning and dewatering. The interactive effects of quicklime dosage, temperature, and time on filter cake's specific resistance to filtration (SRF) and the dewatering rate of oily CRM sludge were studied by response surface methodology (RSM). The optimal parameters for conditioning oily CRM sludge were quicklime dosage of 18.7%, temperature of 54 °C, and time of 43.3 min, which resulted in filter cake SRF of 0.50 × 1010 m/kg and dewatering rate of 61.2%. The viscosity of oily CRM sludge could be reduced by 90% after conditioned with quicklime, which caused by the neutralization or hydrolysis of high viscosity organic matter in the oil phase with quicklime to produce low viscosity organic matter. The study indicated the excellent performance of quicklime as a conditioning agent for oily CRM sludge treatment and provided an effective route for the recycling of the oily CRM sludge for steel production.

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The present study aimed to investigate the effect of cold deformation on the precipitation kinetics of a binary CuSc alloy containing 0.4 wt.% scandium using the experimental analysis method of differential scanning calorimetry (DSC). Non-deformed and 75% cross-section-reduced cold-rolled supersaturated specimens were tested in non-isothermal DSC runs at up to five different heating rates. The DSC results showed that cold rolling significantly accelerated the precipitation process in the binary alloy, leading to a decrease in the initial and peak temperatures of the exothermic reactions. The activation energies calculated with the Kissinger method indicated that the precipitation activation energy decreased with increasing cold deformation. The findings of this study provide worthy implications to further optimize the processing of Cu-Sc alloys with improved mechanical properties.