The Experts below are selected from a list of 66003 Experts worldwide ranked by ideXlab platform
Zhengyi Jiang - One of the best experts on this subject based on the ideXlab platform.
-
A review of microstructure and microtexture of tertiary Oxide Scale in a hot strip mill
Key Engineering Materials, 2016Co-Authors: Xianglong Yu, Jingwei Zhao, Zhengyi Jiang, Ji ZhouAbstract:In hot rolling, metal Oxides formed on steel surface can generally be classified as primary, secondary and tertiary Oxide Scales, corresponding to the reheating stages, the roughing stages and the finishing passes of continuous mills, respectively. The tertiary Oxide Scale grows into the final products on the hot-rolled steel strip during the finishing rolling and the subsequent cooling down to ambient temperature. We provide here a systematic overview of the oxidation mechanism, microstructure and microtexture development of the tertiary Oxide Scale. Mechanism of oxidation and Fe3O4 precipitation in tertiary Oxide has been given as the fundamental theory. Three main sections has been divided in this review. The first section includes experimental investigations on microstructure evolution from the formation of Oxide Scale during hot rolling, then through continuous cooling, to Fe3O4 precipitation behaviour in storage cooling of hot-coiled strip. By using electron backscatter diffraction (EBSD) to characterise both the steel substrate and the Oxide Scale concurrently, the second section has further dealed with the texture-based analysis of Oxide Scale: phase identification, orientation analysis and coincident site lattice (CSL) boundaries. The third section has provided the general type of crystallographic texture and its evolutions in deformed Fe3O4 and steel substrate. Finally, the upcoming challenges have been addressed in this intriguing and promising research field.
-
breakaway oxidation behaviour of ferritic stainless steels at 1150 c in humid air
Corrosion Science, 2016Co-Authors: Xiawei Cheng, Brian J Monaghan, Raymond J Longbottom, Jingwei Zhao, Jianguo Peng, Zhengyi Jiang, Lai Zhu JiangAbstract:Abstract The breakaway oxidation behaviour of ferritic stainless steels 430, 443 and 445 has been investigated at 1150 °C in humid air. The oxidation kinetics exhibited significant differences among the three ferritic stainless steels. A uniform and steady growing Oxide Scale was developed on the 430 steel with an even steel/Oxide interface. Local breakdown of the initially protective Oxide Scale occurred and Oxide nodules were developed on the 443 and 445 stainless steels, resulting in irregular and rough steel/Oxide interfaces. The breakaway oxidation behaviour was significantly influenced by the microstructure and the composition of the Oxide Scale. The Mn-Cr spinel Oxide formed on top of the Cr 2 O 3 Scale in Mo alloying 445 steel can greatly minimise the Cr depletion.
-
effect of a grain refined microalloyed steel substrate on the formation mechanism of a tight Oxide Scale
Corrosion Science, 2014Co-Authors: Xianglong Yu, Jingwei Zhao, Cunlong Zhou, Zhengyi Jiang, Qingxue HuangAbstract:Abstract The formation mechanism of tight Oxide Scale on the microalloyed steel was investigated at temperatures of 550–850 °C in dry air. Microstructural characterisations reveal that the spallation of Oxide Scale dominates at the centre of coarse grains on the oxidation initiation. The fine-grained steel improves the adhesive properties of Oxide Scale by enhanced grain-boundary diffusion. The lower activation energy and higher oxidation rate accelerate cation/anion migration along grain boundaries, leading to high magnetite content in the Oxide Scale. The approach by grain refinement at initial oxidation has been proposed to generate the pickle-free tight Oxide Scale.
-
Experimental Study on Adhesion of Oxide Scale on Hot-Rolled Steel Strip
Advanced Materials Research, 2012Co-Authors: Dongbin Wei, Xiao Dong Wang, Zhengyi JiangAbstract:An experimental method was developed to study the adherence properties of the Oxide Scale formed on microalloyed low carbon steel after hot strip rolling. The evolution of the Oxide Scale during laminar cooling was investigated using Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator. After the sample cooled down to ambient temperature, the Oxide Scale was protected by lacquer to prevent the Scale from losing. Physicochemical characteristics of the Oxide Scale were examined and the adherence mechanism was discussed. Decomposed wustite a mixture of α-iron and magnetite (Fe3O4), can substantially improve the integrity of Oxide Scale. However, large quantities of hematite (Fe2O3) or retained wustite (FeO) were found detrimental to the adhesion of the Oxide Scale. It is found that the adherence of Oxide Scales significantly depends on the phase composition of Oxide Scales with different thickness.
-
The effect of Oxide Scale of stainless steels on friction and surface roughness in hot rolling
Wear, 2011Co-Authors: Dongbin Wei, Anh Kiet Tieu, Jun Xia Huang, Zhengyi Jiang, A. W. Zhang, Xu Shi, Sihai JiaoAbstract:Abstract Friction is one of the most significant physical phenomena influencing metal forming. The deformation or fracture of Oxide Scale significantly affects the roll–strip interface behaviour. Sticking occurs frequently during hot rolling of stainless steels especially ferritic stainless steels, which causes surface defects of both steel products and rolls. It is important to characterize the features of the Oxide Scale in hot rolling of stainless steel strips, but few studies have been carried out. This paper focuses on the deformation of Oxide Scale and roll–strip interface characteristics in hot rolling of austenitic stainless steel 304L and ferritic stainless steel 430. Oxidation tests in a short time in humid air with water vapour content of 7.0 vol.% were carried out using Gleeble 3500 thermo-mechanical simulator, and the oxidation characteristics of 304L and 430 steels were obtained. The deformation, surface morphology of Oxide Scale of the steels, and the friction in hot rolling were studied in hot rolling tests. Thick Oxide Scale of 304L steel shows high lubricative effect while the breaking of thin Oxide Scales of 430 steel may make the steel substrate to contact with the roll, which counteracts the lubricative effect of the Oxide Scale and results in friction coefficient increasing with an increase of reduction. A FEM simulation has been developed to analyse the deformation behaviour of Oxide Scale and surface roughness transfer during hot rolling of stainless steels and the model describing the rough surface profiles of the Scales and steel has been integrated into the simulation.
Dongbin Wei - One of the best experts on this subject based on the ideXlab platform.
-
Experimental Study on Adhesion of Oxide Scale on Hot-Rolled Steel Strip
Advanced Materials Research, 2012Co-Authors: Dongbin Wei, Xiao Dong Wang, Zhengyi JiangAbstract:An experimental method was developed to study the adherence properties of the Oxide Scale formed on microalloyed low carbon steel after hot strip rolling. The evolution of the Oxide Scale during laminar cooling was investigated using Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator. After the sample cooled down to ambient temperature, the Oxide Scale was protected by lacquer to prevent the Scale from losing. Physicochemical characteristics of the Oxide Scale were examined and the adherence mechanism was discussed. Decomposed wustite a mixture of α-iron and magnetite (Fe3O4), can substantially improve the integrity of Oxide Scale. However, large quantities of hematite (Fe2O3) or retained wustite (FeO) were found detrimental to the adhesion of the Oxide Scale. It is found that the adherence of Oxide Scales significantly depends on the phase composition of Oxide Scales with different thickness.
-
The effect of Oxide Scale of stainless steels on friction and surface roughness in hot rolling
Wear, 2011Co-Authors: Dongbin Wei, Anh Kiet Tieu, Jun Xia Huang, Zhengyi Jiang, A. W. Zhang, Xu Shi, Sihai JiaoAbstract:Abstract Friction is one of the most significant physical phenomena influencing metal forming. The deformation or fracture of Oxide Scale significantly affects the roll–strip interface behaviour. Sticking occurs frequently during hot rolling of stainless steels especially ferritic stainless steels, which causes surface defects of both steel products and rolls. It is important to characterize the features of the Oxide Scale in hot rolling of stainless steel strips, but few studies have been carried out. This paper focuses on the deformation of Oxide Scale and roll–strip interface characteristics in hot rolling of austenitic stainless steel 304L and ferritic stainless steel 430. Oxidation tests in a short time in humid air with water vapour content of 7.0 vol.% were carried out using Gleeble 3500 thermo-mechanical simulator, and the oxidation characteristics of 304L and 430 steels were obtained. The deformation, surface morphology of Oxide Scale of the steels, and the friction in hot rolling were studied in hot rolling tests. Thick Oxide Scale of 304L steel shows high lubricative effect while the breaking of thin Oxide Scales of 430 steel may make the steel substrate to contact with the roll, which counteracts the lubricative effect of the Oxide Scale and results in friction coefficient increasing with an increase of reduction. A FEM simulation has been developed to analyse the deformation behaviour of Oxide Scale and surface roughness transfer during hot rolling of stainless steels and the model describing the rough surface profiles of the Scales and steel has been integrated into the simulation.
-
Effect of coiling temperature on Oxide Scale of hot-rolled strip
Advanced Materials Research, 2011Co-Authors: Zhengyi Jiang, Dongbin Wei, Xiao Dong Wang, Quan YangAbstract:The influence of the coiling temperature, ranging from 550 to 570°C, on the morphology and the phase composition of the Oxide Scale formed on the microalloyed low carbon steel for automobiles after hot strip rolling was investigated. Physicochemical characteristics of the Oxide Scales were examined and their formation mechanism was discussed. Thickness of the Oxide Scale is in the range of 8-11µm and decreases with a decrease of coiling temperature. The microstructure and phase composition, XRD analysis shows a large amount of magnetite (Fe3O4) and some sparse hematite (Fe2O3) exist on the surface of hot rolled strip when the coiling temperature reduces from 570 to 550°C. The coiling temperature substantially affects the internal microstructure and magnetite phase.
-
Analysis of Surface Roughness Transformation of Oxide Scale during Hot Steel Manufacturing
Advanced Materials Research, 2010Co-Authors: Zhengyi Jiang, Anh Kiet Tieu, Jianning Tang, Weihua Sun, Dongbin WeiAbstract:In this paper, the effects of the surface asperity wavelength, reduction and lubrication (friction) on the surface roughness transformation of the Oxide Scale have been studied. The simulation results show that the Oxide Scale surface roughness decreases with an increase of the average asperity wavelength and reduction. The initial surface roughness affects the decrease rate of surface roughness when the reduction increases. The surface roughness of the Oxide Scale and steel is quite close when the rolling with lubrication and both of them are reduced with reduction, and the surface roughness of the Oxide Scale is reduced less comparing with that of without lubrication case. The calculated roughness is close to the measured data.
-
Characterisation of thin Oxide Scale and its surface roughness in hot metal rolling
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Zhengyi Jiang, Anh Kiet Tieu, Jianning Tang, Weihua Sun, Dongbin WeiAbstract:The deformation of the thin Oxide Scale formed in hot metal rolling and its surface roughness characterisation are very important for the quality of the finished product. Finite element (FE) simulation of the thin Oxide Scale deformation and surface roughness transfer has been carried out. The authors focus on the surface asperity deformation of the thin Oxide Scale and strip. Surface characterisation and the mechanics of the thin Oxide Scale deformation are obtained from the FE simulation and experimental measurements. Simulation results are close to the measured values. The forming features of surface roughness transfer during hot metal rolling with lubrication are also discussed.
Dihua Wang - One of the best experts on this subject based on the ideXlab platform.
-
Rearrangement of Oxide Scale on Ni-11Fe-10Cu alloy under anodic polarization in molten Na2CO3-K2CO3
Corrosion Science, 2018Co-Authors: Xinhua Cheng, Huayi Yin, Dihua WangAbstract:Abstract The effect of anodic polarization on a pre-formed Oxide Scale of Ni-11Fe-10Cu alloy was investigated in Na2CO3-K2CO3 melt at 750 °C. The pre-formed Oxide Scale rearranged under anodic polarization and enabled the alloy as an inert anode for oxygen evolution. The anodic polarization has a positive effect on repairing defects in the original Oxide Scale, i.e., repair-enhancement effect, which can enhance the protectivity of an alloy substrate and eliminate further corrosion and oxidation. This study demonstrates an effective way to prepare a protective Oxide Scale, and reveals the rearrangement of pre-formed Oxide Scale under anodic polarization.
-
high temperature oxidation behavior of ni 11fe 10cu alloy growth of a protective Oxide Scale
Corrosion Science, 2016Co-Authors: Xinhua Cheng, Huayi Yin, Lei Fan, Li Liu, Dihua WangAbstract:Abstract The oxidation of Ni-11Fe-10Cu alloys in air at high temperature was investigated. A parabolic kinetics was found at 750 °C and a linear kinetics was shown at 850 and 950 °C. The Oxide Scale formed at 750 °C is compact and coherent possessing triplex Oxide layers, i.e., a CuO external layer, a NiFe 2 O 4 middle layer, and a NiO inner layer. A thin copper-rich layer sits between the Scale and alloy substrate, functioning as a barrier for iron and nickel diffusing outwards from the alloy substrate and oxygen ion diffusing inwards. The growth mechanism of the multi-layer Oxide Scale was discussed.
Hiroshi Utsunomiya - One of the best experts on this subject based on the ideXlab platform.
-
Curling of hot-rolled steel sheet caused by surface Oxide Scale
CIRP Annals, 2020Co-Authors: Hiroshi Utsunomiya, Ryo Aizawa, Tomoya Fujimoto, Ryo MatsumotoAbstract:Abstract Rolled sheets may turn up or down after passing the roll gap. The curling occurs under asymmetric conditions, e.g., different roll speeds, diameters, frictions, etc. Even under apparently symmetric conditions, the curling incidentally occurs in hot rolling. In this study, low carbon sheets with controlled upper and lower Oxide Scale were hot-rolled with 15% reduction in thickness. The rolled sheets always curled toward the side with thin Oxide Scale and that severe curling occurred when upper and lower Oxide Scales deformed differently. It is concluded that surface Oxide Scale is a hidden factor to cause curling in hot steel rolling.
-
Influence of uneven interface between steel and Oxide Scale on deformation behavior of Oxide Scale in hot ring compression
Procedia Manufacturing, 2018Co-Authors: Ryo Matsumoto, Yosuke Akiyama, Hiroaki Deguchi, Hiroshi UtsunomiyaAbstract:Abstract In order to control sliding between Oxide Scale and steel in hot forging of steel covered with Oxide Scale, the interface unevennesswas formed between the steel and the Oxide Scale by preparing grooves on the steel surface. The interface unevenness was aimed for improving the anti-peeling characteristic of the Oxide Scale from the steel during the hot forging. The plastic deformation of carbon steel workpiece covered with Oxide Scale was investigated in hot ring compression test. The Oxide Scale was confined between the die and the workpiece, and extended to be radial direction of the workpiece during ring compression test. The expanded ratio of the Oxide Scale formed on the concentric uneven interface was found to be approximately 1.1-1.3 times larger than that on the flat interface at a reduction in height of 50% in ring compression. As the result, the shear friction factor determined from the plastic deformation of the workpiece was reduced in the workpiece with concentric uneven interface by approximately 0.05-0.10, compared with that of the workpiece with flat interface.
-
Reduction of friction of steel covered with Oxide Scale in hot forging
Journal of Materials Processing Technology, 2014Co-Authors: Ryo Matsumoto, Yuta Osumi, Hiroshi UtsunomiyaAbstract:Abstract The hot ring compression test of chrome steel covered with an Oxide Scale film is carried out to examine the effects of the Oxide Scale film on the hot forging characteristics through experiment and finite element analysis. The nominal coefficient of shear friction of the Scale is estimated from the plastic deformation behavior of the chrome steel covered with Oxide Scale film. The estimated coefficient of shear friction of the Oxide Scale is found to be lower than that of the chrome steel. The plastic deformations and temperature changes of the chrome steel workpiece and the Oxide Scale layer are calculated using finite element analysis method to investigate the mechanism underlying the reduction in the friction during the hot forging of chrome steel covered with an Oxide Scale film. Low friction and thermal conductivity values of the Oxide Scale lead to low forging load in the hot forging of chrome steel covered with an Oxide Scale film.
-
Friction in Hot Forging of Chrome Steel Covered with Oxide Scale Film Generated at Steam Atmosphere
Key Engineering Materials, 2014Co-Authors: Ryo Matsumoto, Shohei Harada, Hiroshi UtsunomiyaAbstract:The hot ring compression test of chrome steel covered with an Oxide Scale film is carried out to examine the effects of the Oxide Scale film on the hot forging characteristics. For changing the chemical compositions of the Oxide Scale, the Oxide Scale film is generated at air or steam atmosphere. The nominal coefficient of shear friction of the chrome steel covered with the Oxide Scale film is estimated from the plastic deformation behavior during the ring compression test. The estimated coefficient of shear friction of the chrome steel covered with the Oxide Scale film is found to be lower than that of the chrome steel without the Oxide Scale film. Furthermore, the Oxide Scale generated at steam atmosphere provides lower friction characteristics in comparison with the Oxide Scale generated at air atmosphere. The mechanism of the reduction of friction with the Oxide Scale is discussed.
Anh Kiet Tieu - One of the best experts on this subject based on the ideXlab platform.
-
The effect of Oxide Scale of stainless steels on friction and surface roughness in hot rolling
Wear, 2011Co-Authors: Dongbin Wei, Anh Kiet Tieu, Jun Xia Huang, Zhengyi Jiang, A. W. Zhang, Xu Shi, Sihai JiaoAbstract:Abstract Friction is one of the most significant physical phenomena influencing metal forming. The deformation or fracture of Oxide Scale significantly affects the roll–strip interface behaviour. Sticking occurs frequently during hot rolling of stainless steels especially ferritic stainless steels, which causes surface defects of both steel products and rolls. It is important to characterize the features of the Oxide Scale in hot rolling of stainless steel strips, but few studies have been carried out. This paper focuses on the deformation of Oxide Scale and roll–strip interface characteristics in hot rolling of austenitic stainless steel 304L and ferritic stainless steel 430. Oxidation tests in a short time in humid air with water vapour content of 7.0 vol.% were carried out using Gleeble 3500 thermo-mechanical simulator, and the oxidation characteristics of 304L and 430 steels were obtained. The deformation, surface morphology of Oxide Scale of the steels, and the friction in hot rolling were studied in hot rolling tests. Thick Oxide Scale of 304L steel shows high lubricative effect while the breaking of thin Oxide Scales of 430 steel may make the steel substrate to contact with the roll, which counteracts the lubricative effect of the Oxide Scale and results in friction coefficient increasing with an increase of reduction. A FEM simulation has been developed to analyse the deformation behaviour of Oxide Scale and surface roughness transfer during hot rolling of stainless steels and the model describing the rough surface profiles of the Scales and steel has been integrated into the simulation.
-
Analysis of Surface Roughness Transformation of Oxide Scale during Hot Steel Manufacturing
Advanced Materials Research, 2010Co-Authors: Zhengyi Jiang, Anh Kiet Tieu, Jianning Tang, Weihua Sun, Dongbin WeiAbstract:In this paper, the effects of the surface asperity wavelength, reduction and lubrication (friction) on the surface roughness transformation of the Oxide Scale have been studied. The simulation results show that the Oxide Scale surface roughness decreases with an increase of the average asperity wavelength and reduction. The initial surface roughness affects the decrease rate of surface roughness when the reduction increases. The surface roughness of the Oxide Scale and steel is quite close when the rolling with lubrication and both of them are reduced with reduction, and the surface roughness of the Oxide Scale is reduced less comparing with that of without lubrication case. The calculated roughness is close to the measured data.
-
Deformation of Oxide Scale and surface roughness transfer during hot rolling of stainless steel 304L
International Journal of Surface Science and Engineering, 2009Co-Authors: Jun Xia Huang, Anh Kiet Tieu, Fei Wu, Aiwen Zhang, Zhengyi Jiang, Sihai JiaoAbstract:The oxidation characteristic of stainless steel 304L in humid air and the deformation behaviour of the Oxide Scale during hot rolling at 1050°C were investigated. The surface roughness transfer during hot rolling was discussed. With an increase of reduction, the Oxide Scale thickness decreases linearly, the surface roughness also decreases obviously and the integrity of Oxide Scale increases. The thickness decrease of thick Oxide Scale is more rapid than a thin Oxide Scale. The surface roughness always decreases with an increase of reduction, and the Oxide Scale thickness affects the surface roughness transfer during hot rolling.
-
Characterisation of thin Oxide Scale and its surface roughness in hot metal rolling
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Zhengyi Jiang, Anh Kiet Tieu, Jianning Tang, Weihua Sun, Dongbin WeiAbstract:The deformation of the thin Oxide Scale formed in hot metal rolling and its surface roughness characterisation are very important for the quality of the finished product. Finite element (FE) simulation of the thin Oxide Scale deformation and surface roughness transfer has been carried out. The authors focus on the surface asperity deformation of the thin Oxide Scale and strip. Surface characterisation and the mechanics of the thin Oxide Scale deformation are obtained from the FE simulation and experimental measurements. Simulation results are close to the measured values. The forming features of surface roughness transfer during hot metal rolling with lubrication are also discussed.
-
Modelling of Oxide Scale surface roughness in hot metal forming
Journal of Materials Processing Technology, 2006Co-Authors: Jianning Tang, Anh Kiet Tieu, Zhengyi JiangAbstract:Abstract Oxide Scale formed in hot metal forming and its surface roughness characteristics are very important for the quality of the finished product. In this paper, the Oxide Scale and steel surface roughness changes in hot strip rolling are analysed using the finite element software MSC-MARC package. A model generating a surface roughness profile which reproduces the random characteristics of surface roughness and asperity shape was applied in this study. Surface roughness deformation characteristics of the Oxide Scale are obtained from the finite element simulation. The features of the Oxide Scale surfaces with and without oil lubrication in the roll bite are investigated. Simulation results are compared to the measured values. The rolling temperature effect is also discussed.
