Effect Of Rolling Temperature Research Articles

Effect of rolling temperature on microstructure and mechanical properties of hot-rolled Mg-Al-Ca-Zn-Mn alloys

In order to address the problems of traditional magnesium alloys, such as the easy formation of basal texture and poor plasticity at room temperature, a multivariate micro alloyed Mg-1Al-0.9Ca-0.5Zn-0.4Mn material has been designed by taking advantage of the unique role of solute atoms such as Ca. The effects of its rolling process on grain size, second phase, texture, and tensile properties were compared and analyzed. The results show that the rolling temperature will significantly change the organization and properties: a small number of large-sized reticulate phases, linear phases, and granular phases will exist along the rolling direction inside the Mg-1Al-0.9Ca-0.5Zn-0.4Mn alloy. When the rolling temperature is raised, it will change the number and size of the second phase and microstructure morphology. For three plates rolled at 300°C, the best-combined strength-plasticity mechanical properties were presented in this work; elongation is 2.5%, tensile strength is 167 MPa, and yield strength is 146 MPa along the RD, respectively. Besides, some larger-sized phases still exist in this alloy, which affects its mechanical properties.

Modulation of microstructure and improvement in the mechanical properties of TiBw/Ti65 composites by rolling at different temperatures

The effect of rolling temperature on microstructure evolution and mechanical properties of as-sintered TiBw/Ti65 composites was systematically investigated. The results showed that at 900 °C (in the low α + β phase region), the matrix microstructure primarily exhibited a deformation structure. At 1000 °C (in the high α + β phase region), a bimodal structure was observed, and at 1100 °C (in the β phase region), a basket-weave structure emerged. Additionally, silicides precipitated at 900 °C were fine but grew and coarsened at 1000 °C, eventually dissolving almost completely into the matrix at 1100 °C. This behavior is attributed to the varying solubility of silicides in the α and β phases. With increasing rolling temperature, the dynamic recrystallization (DRX) mechanism within the TiBw/Ti65 composites transitioned from continuous dynamic recrystallization (CDRX) to discontinuous dynamic recrystallization (DDRX). Rolling significantly enhanced the mechanical properties of the composites. The HR-900 composite exhibited the optimal strength-plasticity combination at room temperature, achieving an ultimate tensile strength (UTS) of 1415 ± 21 MPa and elongation (EL) of 6.2 ± 2.7%, mainly due to grain refinement and work hardening. Conversely, the HR-1100 composite demonstrated superior high-temperature mechanical performance, showing improvements of 37.18%, 27.05%, and 9.59% at 963 MPa (650 °C), 789 MPa (700 °C), and 560 MPa (750 °C), respectively, compared to those of the as-sintered materials. The strengthening mechanisms were fine-grain strengthening, dislocation strengthening, and load transfer strengthening of the as-rolled composites, and the primary strengthening mechanism shifts from dislocation to fine-grain strengthening as the rolling temperature increases.

Research on microstructure and mechanical properties of TC4/304 clad plates by asymmetric rolling with local strong stress

In order to solve the problems of complex traditional preparation process and low bonding strength of titanium/steel clad plates, TC4/304 clad plates were prepared by asymmetric rolling with local strong stress (ARLSS), the effect of rolling temperature on the interface bonding of clad plates was studied. The two-dimensional simulation model of TC4/304 clad plates rolling was established by finite element method, and its accuracy was verified by experiments. The experimental results show that the interfacial bonding strength of the clad plates increased with the increasing temperature, but when the temperature reached 950 °C, the brittle intermetallic compounds (IMCs) formed extremely fast, which greatly weakens the bonding strength. The clad plates showed the best bonding strength at 900 °C. After corrugated roll bonding (CRB) (33 % reduction ratio), the bonding strength at the peak was lower than that at the trough. After FRB (46 % reduction ratio), the interface bonding strength was slightly improved. The final peak bonding strength reached 519 MPa, and the trough bonding strength was 527 MPa. The improvement of bonding strength mainly came from the improvement of TC4 matrix strength. The finite element simulation results showed that multiple cross shear zone in the deformation zone of the CRB stage were beneficial to the bonding of dissimilar metals. While the deformation of the clad plates material in the FRB stage was consistent, which effectively avoided the cracking of the bonded area and further improved the bonding strength. Therefore, the strong non-uniform plastic deformation of ARLSS process had a significant effect on the deformation coordination of dissimilar metals and the quality improvement of clad plates.

Effect of Rolling Temperature on Martensitic Transformation and Strain Hardening of Fe–21.2Mn–0.68C Steel

Effect of Rolling Temperature on Martensitic Transformation and Strain Hardening of Fe–21.2Mn–0.68C Steel

Microstructure evolution and mechanical properties of metastable austenitic medium Mn steel fabricated by warm caliber rolling

Warm caliber rolling at 550, 600, and 650 °C were carried out to refine the austenite grains of medium Mn steel by dynamic recrystallization (DRX). The effect of rolling temperature on the microstructure characteristics and mechanical properties of metastable austenitic steel was investigated in detail. The results show that the hierarchical structure of coarse fiber grains (CFGs) and ultrafine grains (UFGs) is obtained by warm caliber rolling method. With the increasing rolling temperature, more obvious DRX behavior occurs, resulting in a high percentage of UFGs. The preactive TRIP effect shortens the yield stress plateau in tensile stress-strain curves caused by CFGs with low stability. Furthermore, the unique hierarchical structure induces crack deflection and delamination, and significantly improves the impact toughness of medium Mn steel at room temperature. However, at the low temperature of −80 °C, CFGs are easy to induce martensite transformation, which seriously deteriorates the impact toughness.

Effect of rolling temperature and reduction on brick-and-mortar Ti2Ni/TiNi composite

The brick-and-mortar Ti2Ni/TiNi composite, composed of Ti2Ni bricks distributed among TiNi mortars, was successfully produced by hot rolling laminated Ti2Ni/TiNi composite. The rolling temperature and reduction have large effects on brick width and brick interspacing, respectively. When the compression is carried out perpendicular to the stacking direction, all the samples exhibit delamination fracture, which is harmful to mechanical performances. When loading is parallel to the stacking direction, too large brick width and too small brick interspacing both boost the delamination between brittle Ti2Ni and ductile TiNi. After 60% rolling at 700 °C, the brick-and-mortar composite exhibits a largest strength of (1923.11±70.78) MPa and a largest fracture strain of 0.190±0.017 because suitable brick width and interspacing inhibit the delamination and promote crack deflection. Further optimization of mechanical properties can be achieved by the adjustment of brick width and interspacing.

The effect of rolling temperature on the microstructure and properties of multi pass rolled 7A04 aluminum alloy

The current research on 7-series aluminum alloys mainly focuses on solid solution and aging treatments, as well as the flow stress during the deformation process. There are limited researches on the influence of thermal deformation temperature on the microstructure and properties of the aluminum alloy during multi-pass hot rolling process. In this study, the as-cast 7A04 aluminum alloy was subjected to homogenization treatment, followed by multi-pass hot rolling. The effects of different deformation parameters on dislocation density were analyzed. Microstructural characterization of the deformed alloy was performed using optical microscopy (OM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and micro-hardness tester. The optimal microstructure of the deformed alloy was selected based on the size of recrystallization. Subsequently, the Deform–3D finite element simulation software was used to analyze the multi-pass hot rolling process. The influence of deformation parameters on the uniformity of equivalent strain distribution within the samples was investigated. The results showed that at the deformation temperature of 430 °C, a significant amount of recrystallized microstructure appeared in the alloy, resulting in the lowest dislocation density and a significant reduction in the quantity of coarse precipitates. Finite element numerical simulation revealed that the deformation temperature had a certain influence on the uniformity of strain distribution within the alloy. However, this influence was mostly eliminated when the deformation temperature exceeded 380 °C. Meanwhile, the distribution of strain within the alloy was found to be related to the temperature distribution.

The Effect of Rolling Temperature and Rolling Ratio on Hardness and TRS of 90μm Grain Size on B4C %5 Reinforcement Copper Matrix Composite

The Effect of Rolling Temperature and Rolling Ratio on Hardness and TRS of 90μm Grain Size on B4C %5 Reinforcement Copper Matrix Composite

Effect of rolling temperature on the occurrence of dynamic strain aging of Inconel 617 superalloy

Inconel 617 specimens were hot rolled at 950 °C, 1050 °C, and 1150 °C to examine the effect of thermomechanical processing on the occurrence of dynamic strain aging (DSA), followed by performing the tensile tests at temperature range of 350 °C–750 °C with the strain rates of 5 × 10−4 s−1, 5 × 10−3 s−1, and 1 × 10−2 s−1. The microstructural evolution was studied by an optical microscope, a scanning electron microscope (SEM), and differential scanning calorimetry (DSC). The stress-strain curves were analyzed in terms of serration intensity and types. The serrated flow at temperature range of 450 °C–750 °C underwent changes by the strain rate and the temperature, and the serration type changed from types A + B and B to type C. The transformation of Portevin-Le Chatelier (PLC) effect from normal to the inverse PLC effect was observed at a temperature higher than 550 °C. The activation energy was calculated and it was found that the diffusion of Cr and Mo substitutional atoms are mainly responsible for the DSA effect in hot rolled Inconel 617 superalloy. The hot rolling temperature was also found to have a significant impact on the occurrence of DSA. Moreover, it was indicated that as the hot rolling temperature increases from 950 °C to 1150 °C, the occurrence of dynamic strain aging is intensified.

Effect of rolling temperature on microstructure and mechanical properties of medium manganese steel

The effect of rolling temperature on the incomplete recrystallization behavior and the relationship to mechanical properties in 0.06C–4Mn-1.2Cr (wt.%) steel was investigated. Three plates of experimental steel were produced by hot rolling at different temperatures and intercritical annealing processes in this study. The microstructure of experimental steels was examined by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The mechanical properties of test steel were examined by impact test and tensile test. Austenite reversion and cementite precipitation-dissolution was numerically simulated under the assumption of local equilibrium. With the decrease of hot rolling temperature from 1000 °C to 800 °C, the uniform equiaxed prior austenite grains microstructures changed to heterogeneous microstructures of laminated and ultrafine prior austenite grains arranged alternatively. The tensile and impact tests revealed that the medium manganese steels rolling at 800 °C had an excellent combination of mechanical properties. Elongation had a great relationship with retained austenite fraction and stability. The fractography of impact specimens was examined to explore the toughening mechanism of the micro-laminated steels. The steel with uniform equiaxed grain structure exhibited a relatively low tensile strength of 750 MPa and low elongation of ∼20% and an extremely poor low-temperature toughness of ∼40 J at −40 °C. An enhanced low-temperature toughness (∼233 J at −40 °C), as well as an improved tensile strength (823 MPa) and higher elongation of ∼40%, was obtained in the steel with heterogeneous microstructures. The content of austenite in heterogeneous microstructure is twice that in uniform equiaxed grain structure. And cementite dissolved more thoroughly in the heterogeneous microstructure. The high austenite content of heterogeneous microstructures enabled the steel to be significantly stronger and ductile, which contributed to the high tensile strength and elongation to some extent. It is concluded that the effect of interface decohesion resulted in the occurrence of delamination. And the high austenite content and delamination greatly improved the low-temperature toughness of experimental steel.

Effect of Rolling Temperature on Microstructure and Properties of Al-Mg-Li Alloy.

In this study, the effects of hot-rolled processes at different temperatures (420 °C, 450 °C, and 480 °C) and subsequent solid solution and aging treatments on the microstructure, mechanical properties, and corrosion properties of Al-Mg-Li alloys with trace Sc and Zr addition were investigated. The aging treatment of rolled sheets after solid solution treatment could obtain Al3Li particles and Al3(Sc, Zr)/Al3Li core-shell particles to improve the mechanical properties of Al-Mg-Li alloy products effectively. The results showed that, as the rolling temperatures increased from 420 °C to 480 °C, the alloy's ultimate tensile strengths and yield strengths increased, while the corrosion resistance decreased. The increase in rolling temperature increased the precipitation-free zone (PFZ) width of the alloy, which undermined the corrosion resistance of the alloy. Moreover, elevating the hot rolling temperature changes the texture strength of the alloy. Particularly in the 480 °C hot-rolled sample, the decrease in the Brass texture strength and the increase in the S texture and Copper texture strength led to an increase in the Taylor factor (M). The increase in rolling temperature also raised the number density of the Al3(Sc, Zr)/Al3Li core-shell particles. The presence of such particles not only inhibits grain growth but also changes the strength mechanism from dislocation cutting to Orowan bypassing. Due to the combination effect of grain morphology, texture evolution, and precipitation behavior, the 480 °C hot-rolled sample had the highest properties.

Effect of Caliber Rolling Temperatures on Microstructure Evolution and Mechanical Properties of High‐Mn Steels

Three kinds of high‐Mn steels are successfully fabricated by caliber rolling at different rolling temperatures, ranging from 773 to 1373 K. The effects of rolling temperature on the microstructure and mechanical properties of steels with different stacking fault energies (SFEs) are studied. With the increase in rolling temperature, the fibrous grains of the high‐Mn steels transform into equiaxed grains, and the microstructure evolution mechanism changes from discontinuous dynamic recrystallization to continuous dynamic recrystallization. The yield strength and microhardness of the experimental samples increase significantly with decreasing caliber rolling (CR) temperature, while the samples sacrifice various degrees of plasticity. Fe–30Mn–4Si–2Al steel with low SFE value fabricated by warm CR has the best microhardness (512 HV) and yield strength (1078.82 MPa), as well as a notable fracture elongation (11.10%) among three experimental steels. This is mainly attributed to the stability of dislocations and the dislocations and twin/ε‐martensite competitive mechanisms.

Effect of deformation microstructures on hydrogen embrittlement sensitivity and failure mechanism of 304 austenitic stainless steel: the significant role of rolling temperature

Metastable austenitic stainless steels (ASSs) have excellent ductility but low strength, so that their usage as load-bearing components is significantly limited. Rolling is an effective method of increasing strength, whereas the effect of rolling temperature on microstructural evolution, the hydrogen embrittlement (HE) sensitivity and fracture mechanisms is still unclear. In present study, the effect of cold/warm rolling on detailed microstructural characteristics of 304 ASS was quantitatively investigated, and the corresponding HE sensitivity was evaluated via slow strain rate test (SSRT). The results suggest that cold-rolling led to high strength but poor plasticity and deteriorated HE sensitivity, while warm-rolled samples provided combination of high strength and ductility and also superior HE resistance. Compared with 18% α′-martensite in cold -rolled steel, warm-rolled specimens consisted of complete austenite, less twins and lower dislocation density，moreover, the favorable {112} ND and {110} ND textures replaced the harmful {001} ND texture. Based on in-situ EBSD observation during SSRT, the HE sensitivity was governed by the combined effect of pre-deformation microstructures and the dynamic microstructural evolution. Advanced method of time-of-flight secondary ion mass spectrometry was used to observe the distribution of hydrogen, and the hydrogen content of specimens was determined by the gas chromatograph thermal desorption analysis method. An exceedingly small amount of hydrogen entered the warm-rolled samples, while a large amount of hydrogen was trapped at grain boundaries of cold-rolled sample, leading to complete intergranular fracture. Therefore, warm rolling is an effective pathway for obtaining high combination of strength and ductility together with excellent HE sensitivity.

Effect of rolling temperature on the recrystallization behavior of 4.5 wt.% Si non-oriented electrical steel

A 4.5 wt.% Si non-oriented electrical steel with a thickness of 0.50 mm was prepared following a conventional process route. Due to the insufficient formability of high-Si steels, this study focuses on the effect of warm rolling temperature on the evolution of microstructure and texture in the hot-rolled sheet after appropriately selected annealing process. The optical microscope (OM) and field emission scanning electron microscope (SEM) with EBSD equipment were utilized to characterize the microstructure evolution during the fabrication process. The results show that the warm rolling temperature significantly impacts the evolution of the microstructure and texture of the 4.5 wt.% Si steel. When rolling at a lower temperature, shear bands appeared within the plate. The shear band vanished as the rolling temperature increased, and obvious delamination can be observed. When further increasing the temperature, the dynamic recrystallization occurred on the surface layer of the plate. The increase of the warm rolling temperature reduced the average grain size after final annealing, and the structural delamination was more obvious. The microstructural characteristics of the warm-rolled sheet affect the subsequent evolution of the texture. Affected by shear bands and delamination, different warm-rolled sheets have different recrystallization textures after final annealing.

Effect of Rolling Temperature on the Structural Refinement and Mechanical Properties of Dual-Phase Heterostructured Low-Carbon Steel

Warm rolling at temperatures ranging from 25 °C to 500 °C was conducted on the dual-phase heterostructured low-carbon steel to investigate the effect of deformation temperature on the structural refinement and mechanical properties. Defying our intuition, the grain size and strength of the rolled steels do not deteriorate with the increase in deformation temperature. Warm rolling at 300 °C produces a much finer lamellar structure and higher strength than steels rolled at both room temperature and elevated temperature. It is supposed that the enhanced interactions between carbon atoms and defects (interfaces and dislocations) at 300 °C promote dislocation accumulation and stabilize the nanostructure, thus helping with producing an extremely finer structure and higher strength than other temperatures.

Effect of Rolling Temperature on the Recrystallization Behavior and Texture Evolution of Mg-14gd-0.5zr Alloy

Effect of Rolling Temperature on the Recrystallization Behavior and Texture Evolution of Mg-14gd-0.5zr Alloy

Effect of rolling temperature on mechanical properties and corrosion resistance of Al-Cu-Mg-Ag alloy

The Al-Cu-Mg-Ag alloy with a low Cu/Mg ratio was hot rolled at different temperatures (410 °C, 440 °C, 470 °C) following by solution and under-aged treatment to reveal the effect of hot rolling temperature on microstructures, mechanical and corrosion properties. This work was investigated by transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and electron backscattering diffraction (EBSD) techniques. The results showed that the tensile strength of the alloy slightly reduced by only 1.5% when the rolling temperature decreased from 470 °C to 410 °C, but greatly improved its corrosion resistance. The strengthening of the alloy mainly came from the synergistic effect of solution strengthening and cluster strengthening. The corrosion susceptibility of the alloy hot rolled at a lower temperature was suppressed, due to the increase in the low-angle grain boundary (LAGB) fraction and the discontinuous distribution of the precipitated S phases at the grain boundary. It was also found that Ag atoms were segregated at the grain boundary by mapping.

Preparation of Ti/Al composite plates by differential temperature rolling with induction heating

In the current study, we proposed a method of differential temperature rolling with electromagnetic induction heating to prepare Ti/Al composite plates in a protective atmosphere to realize the homogeneous deformation of Ti/Al bonding rolling and improve the interfacial bonding strength of the composite plates. The temperature field required for homogeneous deformation rolling of titanium and aluminum was constructed using finite element simulation by adjusting the parameters of electromagnetic induction heating, which made a temperature difference of about 632 °C between titanium and aluminum, and the temperature of each plate was relatively uniform. The induction heating experiment was designed based on the finite element simulation, and the experiment verified the accuracy of the simulation results. The effects of rolling temperature and reduction rate of homogeneous deformation and bonding strength of Ti/Al composite plates were evaluated by rolling experiments. With the increase of rolling temperature and reduction rate of titanium, when the heating temperature of the Ti plate is 750–850 °C, and the reduction rate is 30%–48%, the reduction rate of Ti plate and Al plate gradually tend to be the same. When the titanium plate and aluminum plate temperature is 850 °C and 188 °C, respectively, with a rolling reduction rate of 48%, the deformation rate of Ti plate and Al plate is 46.8% and 48.6%, respectively. Moreover, the bonding strength of the composite plate reaches 77MPa.

Effect of Rolling Temperature and Subsequence Ageing on the Mechanical Properties and Microstructure Evolution of an Al-Cu-Li Alloy

The mechanical properties and microstructure evolution of an Al-Cu-Li alloy sheet processed via hot rolling (HR) (at 400 °C and 500 °C) or cryorolling (CR) (at −100 °C and −190 °C) and subsequence aging at 160 °C for 10 h were investigated. Before aging, the highest ultimate tensile strength of 502 MPa was achieved when the sheets were cryorolled at −190 °C, while the better ultimate tensile strength of 476 MPa and the best elongation rate of 11.1% was achieved simultaneously when the sheets were cryorolled at −100 °C. The refined grains and numerous uniform deformation-induced dislocations microstructures were responsible for the improved strength and enhanced ductility of the cryorolled sheets compared to that of the alloy processed by hot rolling with a low dislocation density zone (LDDZ) and high dislocation density zone (HDDZ). After aging at 160 °C for 10 h, the ultimate tensile strength further improved resulted from the greater precipitation strengthening, and the increased precipitates provided greater resistance to dislocations movement resulting in the increased ductility although the dislocation density decreased. The uniform dislocation microstructures in the cryorolled sheets provide numerous nucleation sites for the precipitates, leading to higher strength after aging.

Effect of Rolling Temperature on Room Temperature Formability and Texture Formation of Mg-3 mass％Al-1 mass％Sn Alloy Sheet

Effect of Rolling Temperature on Room Temperature Formability and Texture Formation of Mg-3 mass％Al-1 mass％Sn Alloy Sheet