Hot Rolling Tests Research Articles

The Development of Advanced Fluorescent Tracers Aimed at Drill Cuttings Labelling and Depth Correlation via Injection with Oil-Based Drilling Mud

Fast and precise geo-steering and geo-navigation upon well drilling are the key parameters for improved well targeting, optimal well placement, and maximal hydrocarbon recovery. To advance geo-steering parameters, we propose a new approach to on-site formation evaluation through the use of fluorescent tracers for drill cuttings tagging according to the depth of origin. Cuttings labelling at the drill bit site is followed by near-real-time drilling depth correlation at the well-head via a camera and AI image recognition systems. To suite the drilling process, the engineered tracers should match to the rheology of the utilized drilling mud. This study was performed to comprehensively investigate the effect of fluorescent tracers on the rheological properties of oil-based drilling mud (OBM) and to determine the optimal quantities of the tracers’ addition. We evaluated critical mud characteristics including electrical stability, thixotropic parameters, shear stress, gel strength, plastic viscosity, and yield point as prepared and in the presence of fluorescent tracers at the range of 1 to 20 wt.%. Additionally, the mud’s effects on the long-term stability of the fluorescent tracers were assessed via hot-rolling tests in conditions mimicking downhole conditions, with the aim of determining the tags’ feasibility for drill cuttings labelling applications. The study also examines the recovery potential of the tracers and their reusability in the drilling process. This investigation provides valuable insights into the potential application of fluorescent tracers for downhole drill cuttings depth correlation which will improve geo-steering works.

Twin-Roll Casting as a Grain Refinement Method and Its Influence on the Microstructure and Deformation Behavior of an AZ31 Magnesium Alloy Wire

Due to a combination of casting and rolling in one process step, twin-roll casting is an effective grain refinement method. This study compares the direct-chill cast (DC) state and the twin-roll cast (TRC) state of an AZ31 magnesium alloy in different steps regarding the microstructure, deformation behavior, and mechanical properties. In the initial state, the TRC AZ31 exhibits a significantly finer grain size and a slight rolling texture compared to the DC AZ31. Therefore, the TRC materials exhibit higher strengths and ductility. After a short heat treatment of 400 °C and 12 h for the DC state and 460 °C and 15 min for the TRC state, cylindric compression tests of the heat-treated samples were conducted at different temperatures (300–400 °C) and strain rates (0.1–10 s−1). To reproduce the deformation behavior at higher strain rates, hot rolling tests (350 °C, 15 s−1) of the heat-treated samples were performed. For both alloys, discontinuous dynamic recrystallization and twinning-induced dynamical recrystallization could be detected. A fine grain size and similar strengths were present after five passes. The AZ31 TRC exhibited a higher ductility due to a higher texture intensity, as the stress direction corresponds to the rolling direction in the case of tensile testing.

The influence of water-based nanolubrication on mill load and friction during hot rolling of 304 stainless steel

Using pure water in comparison to water-based lubricant containing 4% TiO2 nanoparticles (NPs), the hot rolling tests of 304 stainless steel were carried out at a rolling temperature of 1050 °C under varying rolling reductions and speeds. The effects of lubrication on rolling force, torque, power and contact friction were systematically investigated. The coefficient of friction (COF) during steady-state hot steel rolling was inversely calculated using a developed flow stress model. The COF models including the effects of rolling reduction and speed were proposed via multiple linear regression. The results indicated that the use of the nanolubricant enabled a reduction of rolling force up to 6.1% and decreases in rolling torque and power up to 21.6%, compared to that of water condition. The results obtained from the linear regression agreed well with those from the inverse calculation, suggesting the developed COF models had high accuracy. The lubrication mechanisms were derived from a boundary lubrication regime, owing to ball bearing and mending effects of TiO2 NPs, and formation of thin lubricant film under high rolling pressure.

Metallographic structure improvement of hot rolled strip induced by high temperature diffusion of MoS2 nano-lubricant

To improve metallographic structures and lubricating properties of hot rolled strips, a multifunctional MoS2 nano-lubricant was proposed for hot rolling process. Through hot rolling tests and relevant characterization methods of energy dispersive spectrometer (EDS) and field-emission scanning electron microscopy (FESEM), the multifunctional MoS2 nano-lubricant was proved to have both improved metallographic structures and lubricating properties. Not only the rolling forces were decreased, the thickness of oxidized scale was also reduced from 30–35 μm to 16–18 μm by using the MoS2 nano-lubricant. The grains in metallographic structure were observed to be refined obviously, and the orientations of pearlite lamellae were more multidirectional. There were also some carbide precipitates with dispersion strengthening effect appeared around grain boundary. The presence of Mo atoms within the iron matrix indicates the improved metallographic structure as a result of the diffusion of MoS2 nanosheets. This behavior is further instigated using thermal diffusion test, hot compression test, and molecular dynamics (MD) simulation. The results show that the metallographic structure improving effect of multifunctional MoS2 nano-lubricant was attributed to the interaction between MoS2 nanosheets and strips under the high-temperature and high-pressure condition of hot rolling process. In the presence of such high pressure, Mo atoms in MoS2 nanosheets could diffuse through the oxidized scale and exist in the iron matrix. The interaction between Fe and MoS2 nanosheets, meanwhile, was stronger. The diffused Mo atoms in iron matrix could form some coordination complexes with Fe atoms, which promote the nucleation of cementite, and playing a role in grain refinement. Therefore, the bifurcation growth was significantly enhanced, thus the growth directions of pearlite were also increased significantly. The researches provided not only theoretical basis for the development of multifunctional nano-lubricant with integrated metallographic structure improving effect, but also a new path for surface strengthening of strips.

Preparation, performance and mechanism of 3-aminopropyltriethoxysilane modified graphene oxide as nano shale swelling inhibitor

Wellbore instability is a challenging technical problem in drilling operation, shale inhibitor can effectively inhibit shale hydration and dispersion, so as to stabilize the wellbore of shale. In this paper, graphene oxide was prepared by Hummer’s method, and modified by 3-aminopropyltriethoxysilane. The structure of modified graphene oxide was characterized using FT-IR and TGA, and the results showed that modified graphene oxide has been successfully prepared. The inhibitive performance was investigated by the linear swelling and hot-rolling tests, which shows the swelling rate of artificial core is reduced by 10.32% in 2.0% inhibitor solutions and the shale rolling recovery rate was reached 90.13% in 3.0% inhibitor solutions at the rolling condition of 120 °C × 16 h. Finally, the inhibition mechanism was studied, inhibitor can enter into the interlayer of shale and change the appearance of bentonite by physical and chemical interaction, and in that way achieve a good inhibition result.

Water‐based Cu nanofluid as lubricant for steel hot rolling: Experimental investigation and molecular dynamics simulation

AbstractThe lubrication performance of Cu nanofluid was studied through hot rolling tests and non‐equilibrium molecular dynamics simulation. Results showed that nanofluid with 0.5 wt% Cu nanoparticles possessed the optimal effect in reducing the rolling force, finish rolling thickness and rolled surface roughness. The superior lubrication performance was attributed to the formation of protective tribofilm made of Fe/Cu debris, iron and copper oxides as well as amorphous substances with a thickness of about 24 nm, which avoided the direct contact of steel strip and the roll, thus inhibiting the adhesion wear. Molecular dynamics simulation disclosed that the rolling‐dominated motion pattern of Cu nanoparticles with 74.1% rolling and 25.9% sliding motion contributed to a significant decrease in the friction force. Besides, surface defects including the peaks and valleys were polished and repaired by nanoparticles respectively, thus developing the surface quality of hot rolled products.

Effect of Multipass Hot Rolling on the Grain Uniformity of a 316L/EH40 Composite Plate

The grain uniformity of a 316L/EH40 composite plate during multipass forming was studied by numerical simulation and hot rolling tests. In view of the total fixed deformation with a different number of passes, grain size variations on the surface, in the center, and at the interface of the base layer, and those on the surface and at the interface of the clad layer after rolling were simulated and analyzed. The rolling schedule was established to meet the adequate uniformity level of the base and clad layers. The most effective process was verified by the vacuum hot rolling test of a four-layer symmetrical billet. The metallographic images were taken in different locations of the composite plate, and the grain sizes in the images were measured by the cut-point method. Experimental results were compared with simulation data, demonstrating their reliability; the error between them was maintained within 5.5%.

Hot Processing of Powder Metallurgy and Wrought Ti-6Al-4V Alloy with Large Total Deformation: Physical Modeling and Verification by Rolling

The influence of the total deformation amount on the microstructure and selected properties of Ti-6Al-4V alloy was determined in this study. Multi-axis compression tests on the MaxStrain module were performed to obtain large strains. Starting material for the research was obtained by the powder metallurgy (PM) route. Plastically processed cast alloy of the same chemical composition as PM alloy was also tested as reference material. The tests were performed with the cooling of samples between successive deformation stages, which allowed for the simulation of the temperature drop occurring during industrial processes. The multi-stage deformation ability of PM Ti-6Al-4V alloy without decohesion was confirmed. It has also been shown that the application of increasing total strain at a controlled temperature changes the samples resulting in the refinement of the microstructure and leads to the fragmentation of lamellae. The results obtained from MaxStrain tests were verified by multi-stage hot-rolling tests. Defect-free products were obtained, whose good quality was confirmed by the microstructural observations as well as by the investigations of their properties. The results of the rolling tests confirmed the possibility of hot processing of Ti-6Al-4V alloy compacts in industrial conditions, applying large total strain.

Preparation and application of a novel polyammonium as potent shale hydration inhibitor

In this paper, a novel shale hydration inhibitor polyammonium abbreviated as DEP was prepared by piperazine, epichlorohydrin and dimethylamine, and evaluated by anti-swelling experiments, linear expansion tests, mud ball experiments, hot rolling tests and particle size experiments. Anti-swelling results showed that anti-swelling rate of DEP-7 have reached up to 86.30% when its concentration was 0.8 wt%. Mud ball experiments showed that the polyammonium has strong inhibition ability to inhibit bentonite hydration swelling and control the particle size of bentonite. Thermo gravimetric analysis and scanning electron microscope was used to study its inhibition mechanism. Results demonstrated that DEP-7 can be adsorbed on clay surface through electrostatic interaction and hydrogen bonds by anchoring effect and hydrophobic effect.

Evaluation of a naturally derived tannin extracts biopolymer additive in drilling muds for high-temperature well applications

The formulations of drilling fluids using conventional clays are often faced with difficulties in the control of rheology, filtration and gelation, owing to the flocculation of the clay at the temperature above 250 °F. In this study, tannins were extracted from the bark wastes of Rhizophora Mucronata spp. (RMTE) and used as a deflocculant to formulate water-based muds (WBMs). The efficacy of reducing the gelation and viscosity of WBMs with the extracted RMTE was compared with commercial Modified Desco Tannin (MDT). The RMTE was characterized using Fourier-transform infrared spectroscopy (FTIR). Rheological and filtration control properties tests were conducted on the RMTE and MDT mud samples before and after hot rolling tests at different temperatures of 225 °F, 250 °F, 275 °F and 300 °F. FTIR test data indicate the presence of different active functional groups in the RMTE structure, especially the hydroxyl (–OH) groups, which are responsible for the good thinning ability of the RMTE. Experimental data of the WBM after hot rolling tests with 8 g concentration at 300 °F show a 43.5% reduction of plastic viscosity with MDT and 50% reduction with RMTE. With a concentration of 2 g, the yield point of the WBM with commercial MDT and locally derived RMTE at 225 °F before hot rolling tests reduced by 50% and 57.1%, respectively. Furthermore, the addition of RMTE and MDT to the WBM reduced the filtrate volume and the gel strength. The experimental data indicate that the RMTE shows better deflocculating performance compared to that of the MDT, illustrating the need for its application in WBMs for high-temperature wells.

Application of a novel acrylamide copolymer containing highly hydrophobic comonomer as filtration control and rheology modifier additive in water-based drilling mud

Deep wells suffer from the instability and disintegration of natural polymers and other commonly used additives under high pressure and high temperature condition. As a result, serious problems such as hydraulic loss, stuck pipe, and high torque and drag are expected to take place which leads to a dramatic increase in cost and time. This study presents the functionality of a novel synthetic based acrylamide-styrene copolymer (SBASC) as a supersede additive for water-based drilling mud. First, the SBASC was synthesized using an emulsion polymerization process and its particle morphological and polymer chain structural properties were determined by Field Emission Scanning Electron Microscopy (FESEM) and Fourier- Transform Infrared Spectroscopy (FTIR), respectively. Then, the designated copolymer was added into a mud formulation which is applicable in oil and gas fields, and its performance in the mud was investigated with respect to filtration properties and rheological characteristics. In addition, the rheological characteristics and filtration behavior of drilling fluids containing SBASC were compared with those of a field applicable fluid that contained 9 g of HT starch which is a commercial natural polymer commonly used in drilling fluid industry. Furthermore, the thermal stability of SBASC was determined by conducting hot rolling and high pressure-high temperature (HP-HT) filtration tests. The obtained results confirmed that the addition of the copolymer enhances the rheological characteristics of the drilling fluid before and after aging at 121.1 °C. Moreover, the filtration behavior at both conditions was improved by introducing SBASC into the fluid, while the best performance was observed for the fluid containing 3 g of SBASC which shows 38.8% and 47.5% fluid loss reduction for HP-HT and LP-LT conditions, respectively. Furthermore, the solubility of SBASC in saline and fresh water is verified by demonstrating a promising solubility in high salinity water sample with different concentrations of a monovalent salt.

Insights into the behavior of polyphosphate lubricant in hot rolling of mild steel

Hot rolling with a large reduction is usually performed to produce the fine-grained strips, which leads to a severe wear of work roll and affect substantially the strip quality. As a result, lubricants are usually introduced to reduce these problems, with inorganic polyphosphate glass polymer showing the most promising prospective. This study aims to provide a new insight into the lubrication film at roll/strip interface in hot rolling. A series of lubricated hot rolling tests were performed by a 40wt% sodium metaphosphate aqueous solution under 20–60% reduction, at 950–1150 °C and 0.5 m/s. Thermal behaviors of sodium polyphosphate and the rolled strip samples were analyzed by high temperature laser confocal microscope, Secondary Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDX), Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) etc. The results reveal that the lubrication film thickness at the roll/strip interface varied from 0.6 to 4.3 µm with the rolling load being reduced up to 6.1% and friction coefficient up to 16%. FIB and TEM analysis reveal that the polyphosphate film has an amorphous structure which was penetrated through by the oxide scale. It had been found that the polyphosphate lubrication performance was improved at a higher reduction and temperature, which contributes to the friction and oxidation-reduction.

Performance Evaluation and Lubrication Mechanism of Water-Based Nanolubricants Containing Nano-TiO2 in Hot Steel Rolling

Hot rolling tests of a low-alloy steel were conducted at a rolling temperature of 850 °C under different lubrication conditions, including benchmarks (dry condition and water) and water-based nanolubricants containing different concentrations of nano-TiO2 from 1.0 to 8.0 wt%. The effects of nanolubricants on rolling force, surface roughness, thickness of oxide scale, and microstructure were systematically investigated through varying nano-TiO2 concentrations. The results show that the application of nanolubricants can decrease the rolling force, surface roughness and oxide scale thickness of rolled steels, and refine ferrite grains. In particular, the nanolubricant containing an optimal concentration (4.0 wt%) of nano-TiO2 demonstrates the best lubrication performance, owing to the synergistic effect of lubricating film, rolling, polishing, and mending generated by nano-TiO2.

Effects of oil-in-water based nanolubricant containing TiO2 nanoparticles in hot rolling of 304 stainless steel

In this paper, oil-in-water (O/W) based nanolubricants containing TiO2 nanoparticles were developed to reduce the rolling force and improve the surface quality of rolled 304 stainless steel product. Practical hot rolling tests with and without application of lubricant were conducted to systematically investigate the effects of the developed O/W based nanolubricants on the rolling force, surface roughness, oxide scale thickness and tribological behaviour. The obtained results indicate that the nanoparticles can enter the deform zone with oil droplets to take a lubrication effect. The optimal lubrication effect can be achieved when the O/W (1% oil mass fraction) based nanolubricant with a TiO2 mass fraction of 1.5% was applied. The microstructure of oxide scales formed on the hot rolled sample was not significantly affected by TiO2 nanoparticles in the O/W based lubricant, but the oxide scale growth could be induced by TiO2 nanoparticles. A discontinuous thin SiO2 layer at the substrate-scale interface was observed. It can effectively reduce the formation of iron-rich oxides. The novel nanolubricant has a great potential to be applied in the hot steel rolling, to realise the cost-effective and environmental-friendly manufacturing process.

Numerical Simulation and Experimental Study on the Interface Bonding of Stainless Steel Clad Plate

The rolling temperature and rate of thickness reduction directly affect the interface bonding quality,mechanical properties and microstructure of stainless steel clad plate. In order to obtain reasonable rolling process parameters, the multi-pass rolling processes of Q345R/316L stainless steel clad plate were simulated by the DEFORM software package. The distributions of stress, strain, and microstructure fields of the clad plate at different rolling temperatures and reduction rates were investigated. The bonding state of the interface was determined and the change rules governing the grain size of the rolled substrate layer also were analyzed. Vacuum hot-rolling tests were carried out to characterize the microstructure and mechanical properties. It was found that the higher the rolling temperature, the lower was the reduction rate needed to realize the interface bonding. However, too high temperatures produce a higher fraction of coarse grains, which affects the overall mechanical properties of the clad plate. It was concluded from the tests and numerical results that rolling temperature of 1150°C and reduction rate exceeding 50%, stainless allow one to produce steel clad plates with high interface bonding quality and excellent microstructure.

Analysis of TiO2 nano-additive water-based lubricants in hot rolling of microalloyed steel

Hot rolling tests of microalloyed steel were performed at rolling temperatures of 1050, 950, and 850°C under different lubrication conditions, including dry, water lubrication, and 1.0 vol.% oil-in-water (O/W) emulsion. The rolling force, surface roughness, and thickness of the oxide scale of the rolled steel were investigated in order to evaluate the lubrication effects of TiO2 nano-additive water-based lubricants. The results show that the rolling force under a rolling temperature of 1050°C does not vary significantly under all the lubrication conditions. The 4.0wt.% TiO2 water-based lubricant, however, leads to the lowest rolling force at rolling temperatures of 950 and 850°C. The application of 4.0wt.% TiO2 water-based lubricant in hot rolling not only produces the best surface finish, but also results in the thinnest oxide scale of the rolled steels. The lubrication mechanisms of TiO2 nano-additive water-based lubricants in hot rolling were also discussed.

Effects of surface preparation on tribological behaviour of a ferritic stainless steel in hot rolling

Some defects on the surface of carbon steel do not need to be removed before hot rolling because the surface will be vigorously oxidised in a reheating environment. Thus the defects can be minimised by oxidising and then removed by the de-scaling process. The defects on the surface of ferritic stainless steels, however, are not easily removed by oxidation when a high chromium concentration is used. In this paper, a ferritic stainless steel grade 445 was selected as a research material. The effects of different surface features on oxidation and tribological behaviour in the hot rolling process were investigated. Three surface states were prepared, namely, smooth surface, surface with 45° grinding marks and surface with oscillation marks. The samples were put into an electric furnace at 1100°C for reheating. Hot rolling tests were carried out on a 2-high Hille 100 experimental rolling mill. Rolling forces were measured, and the coefficient of friction was calculated and compared under various rolling parameters. It was found that the original surface profiles with grinding marks were still maintained during oxidation. The original oxide scale on the surface with oscillation marks caused the formation of irregular oxide nodules and the spallation of the oxide scale. Surface morphology and the reduction in thickness had a significant impact on the oxide scale integrity and coefficient of friction in the hot rolling process.

Effects of oil-in-water based nanolubricant containing TiO 2 nanoparticles in hot rolling of 304 stainless steel

Energy saving and improvement of product quality are of crucial importance in hot rolling of 304 stainless steel. In this paper, oil-in-water (O/W) based nanolubricants containing TiO2 nanoparticles were developed to reduce the rolling force and improve the surface quality of rolled 304 stainless steel product. Practical hot rolling tests with and without application of lubricant were conducted to systematically investigate the effects of the developed O/W based nanolubricants on the rolling force, surface roughness, oxide scale thickness and tribological behaviour. The obtained results indicate that the nanoparticles can enter the deform zone with oil droplets to take a lubrication effect. The optimal lubrication effect can be achieved when the O/W (1% oil mass fraction) based nanolubricant with a TiO2 mass fraction of 1.5% was applied. The novel nanolubricant has a great potential to be applied in the hot steel rolling, to realise the cost-effective and environmental-friendly manufacturing process.

Study on Tribological Property of Nano-TiO<sub>2</sub> Additive Oil-in-Water Lubricant during Hot Rolling

Oxide scale formed on the steel surface during hot rolling affects the tribological property of nanoTiO2 additive oil-in-water (O/W) lubricant, resulting in changes of roll forces, torques and power consumption, as well as the wear and the surface quality of the work roll and workpiece in hot rolling. The nanoparticle additive O/W emulsion is a novel lubricant and has a great potential to be used in hot rolling process. However, little research has focused on the nanoparticle additive O/W emulsion. In this study, oxidation, tribological and hot rolling tests were conducted to investigate the tribological behaviour of nanoTiO2 additive O/W lubricant. The results indicate that the surface morphology of the oxide scale plays an important role in tribological behaviour of nanoTiO2 additive O/W lubricants. The coefficient of friction (COF) and rolling force are reduced with the addition of nanoTiO2 particles into the 1.0% (mass %, oil concentration) O/W lubricant. This study is helpful in applying the nanoTiO2 additive O/W lubricant during hot rolling to realise reduction of rolling force and power consumption.

Effect of Boron Addition on Microstructural Evolution and Room-Temperature Mechanical Properties of Novel Fe66−x CrNiB x Si (x = 0, 0.25, 0.50 and 0.75 Wt Pct) Advanced High-Strength Steels

In this study, the Vickers hardnesses and room-temperature uniaxial tensile behaviors of four Fe66−x CrNiB x Si (x = 0 (0B), 0.25 (25B), 0.50 (50B), and 0.75 (75B) wt pct) advanced high-strength steels (AHSSs) in the as-hot-rolled and heat-treated (1373 K (1100 °C)/2 h + 973 K (700 °C)/20 min) conditions were investigated. Microstructural evolution after solidification, hot rolling, heat treatment, and uniaxial tensile tests of 0B, 25B, 50B, and 75B AHSSs was also characterized using field emission gun scanning electron microscopy and X-ray diffraction. The tensile behaviors of the 0B, 25B, 50B, and 75B AHSSs were manifested by an excellent combination of strength and ductility over 34.7 and 47.1 GPa pct, 36.9 and 42.3 GPa pct, 45.9 and 46.4 GPa pct, and 11.9 and 47.8 GPa pct, respectively, arising from microband-induced plasticity in the 0B, 50B, and 75B AHSSs and transformation-induced plasticity in the 25B specimens. All specimens in the as-hot-rolled and heat-treated states showed an austenitic matrix grain. Adding boron to the base alloy (0B) resulted in grain refinement, M2B dispersion, precipitation hardening, and solid solution strengthening, which led to an increase in strength. The results of the present work show promise for automotive applications that require excellent properties and reduced specific weight.