科创中国

Huang Qingxue;Jiang Zhengyi

Advanced Materials Research

2011

The effects of β-Mg17Al12on the edge crack behavior of twin-roll casting AZ31B magnesium alloy plate were studied by optical microscope, field emission scanning electron microscope and tensile testing. The results indicate that in the surface and the edge of AZ31B magnesium alloy cast-rolling plate, β-Mg17Al12phase mainly distributes at the grain boundary and its density is big, forming net-shape; and in the center and the middle of the plate, spherical β-Mg17Al12phase disperses in α-Mg matrix, and forms lamellar-shape; the net-shaped β-Mg17Al12phase in the plate can decrease the mechanical properties, while the lamellar-shaped β-Mg17Al12phase improve its ductility. The bonding force between the β-Mg17Al12phase and the α-Mg matrix in the grain boundary is bad and characterized by brittleness. In the deformation of roll casting process, first of all, β-Mg17Al12phase separates from the α-Mg matrix, resulting in crack initiation and propagation in grain boundary; rolling pressure and friction produces tensile strain accumulation in the rolling region, and passes to the solidification shell which is on the both sides of liquid region (i.e. the slab edge), making grains break or tear along the grain boundary β-Mg17Al12phase to deepen longitudinally and as a result the edge crack forms.

Huang Zhiquan;Huang Qingxue;Ma Lifeng;Lin Jinbao;Pang Zhining

Xiyou Jinshu Cailiao Yu Gongcheng Rare Metal Materials and Engineering

2014

© 2014 Central Iron and Steel Research Institute. Stainless steel (SS)/carbon steel (CS) clad plates were generated by means of the all-around weld of interface and vacuuming (AAWIV) followed by hot rolling, wherein AAWIV was utilized for controlling the interface oxidation during hot rolling. The structure near the interface was analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical properties of SS/CS clad plates were investigated by tensile and shear as well as bend tests. The SS/CS interface is relatively flat and no visible separation appears. Line scanning analysis shows that diffusion of Cr and Ni from SS to CS and C from CS to SS occurred during bonding. Higher dislocation densities are observed in both layers of parent plates adhering to the interface. The SS/CS clad plates reveal higher yield, tensile and shear strengths. Both macroscopic delamination at the interface and fracture of base CS as well as intergranular fracture appearance of flyer plate are observed in the tensile test. The shear specimen fails in a ductile manner and the bend specimen tested shows no visible crack at the interface. Taking both interfacial structure and mechanical properties into account, the SS/CS clad plates exhibit sound bonding by the process of AAWIV and hot rolling.

Huang Qing-xue;Yang Xiao-rong;Ma Li-feng;Zhou Cun-long;Liu Guang-ming;Li Hai-bing

Journal of Iron and Steel Research International

2014

© 2015 ISIJ. Oxide scale formed on the strip surface during hot rolling has posed a serious obstacle to ensure a defect-free surface of steel products in an ecologically friendly way. Recently, an influential idea is that the tertiary oxide scale with a tailored texture can be expected to enhance surface quality and tribolgoical properties during particular lubrication. In this study, texture evolutions of magnetite (Fe3O4) and hematite (α-Fe2O3) in deformed oxide layers formed on a hot-rolled microalloyed steel were investigated by electron back-scattering diffraction (EBSD). Fe3O4 develops a strong θ fibre parallel to the oxide growth, and α-Fe2O3 has a dominant {0001}>101 0> texture component. This could be explained by surface energy minimisation during oxides growth and transformation between two oxides, which can also be affected by propagation of cracks along high angle grain boundaries in Fe3O4. Our data further demonstrate that a high thickness reduction (>28%) can reduce α-Fe2O3 wedging through Fe3O4 cracks, and tailoring Fe3O4 texture to {111} components can prevent the α-Fe2O3 growth titling 54.76° from the >001> crystal direction of Fe3O4. As such, these means can dramatically alleviate disturbance from 'red scale' (α-Fe2O3) during high-temperature steel processing.

Yu Xianglong;Jiang Zhengyi;Zhao Jingwei;Wei Dongbin;Zhou Cunlong;Huang Qingxue

ISIJ International

2015

©, 5015, Xi'an Jiaotong University. All right reserved. According to the bar straightening process features and wear area of straightening roll, the design method of “three-stage concave roll and two-stage convex roll” was put forward to improve the straightening accuracy of two-roll straighter. In the design process, based on the bar deformation rule, the principle of 5εt fitting was put forward to describe the stress-strain relationship more accurately and effectively. On the basis of fitting rule and micro-element method, the stress state of metal inside the bar and the neutral layer offset were analyzed, then the bending moment ratio including hardening coefficient and neutral layer offset was deduced. From the comprehensive analysis of the relation of straightening force with the roller wear, as well as the effects of residual stress and elastic core on the hidden deflection, the range of reverse bend curvature ratio of roller lumbar segment was determined for different bar sizes, and hence the wear of roller surface could be slowed down, and the defect of unstable straightening quality caused by residual stress response was overcome greatly. Based on the proposed theory and method, the specific design example was provided to simulate the straightening process, and each parameter which might affect the straightening accuracy was analyzed. It can be found that the straightening accuracy of the designed roll shape could reach to 0.64 mm/m, the hidden deflection was 0.2024 mm/m, and the prediction accuracy after straightening was less than 0.85 mm/m. The stability and reliability of the bar straightening were guaranteed, and the correctness and effectiveness of the theory and design method were verified.

Ma Lifeng;Ma Ziyong;Ma Lidong;Huang Qingxue;Ma Bing;Wang Yufeng

Hsi an Chiao Tung Ta Hsueh Journal of Xi an Jiaotong University

2015

© 2016 IOP Publishing Ltd. Highly textured Heusler alloy Mn44.7Ni43.5Sn11.8 ribbons were prepared by melt spinning. The magnetoresistance (MR) properties were evaluated by the magnetic field perpendicular to the ribbon surface with the field up to 30 kOe. A large MR (about 25%) with a lower magnetic field (10 kOe) was obtained at 276 K. Due to the rapid solidification. The ribbons with a specific texture can get a large MR twice than polycrystalline alloys at the same magnetic field. The highly textured Mn-Ni-Sn melt spun ribbons may be broadly applied in magnetic memory and as temperature and magnetic sensors as well.

Chen Fenghua;Huang Qingxue;Jiang Zhengyi;Zhang Mingang;Zhao Jingwei;Xuan Haicheng;Xu Xiaohong

Smart Materials and Structures

2016

© 2016 Chinese Physical Society and IOP Publishing Ltd. Highly textured Heusler alloy Mn46Ni42Sn11Sb1 ribbons were prepared by melt spinning. The annealed high Mn content Mn46Ni42Sn11Sb1 ribbon cross-section microstructure, crystal structure, martensitic transformation (MT), and magnetoresistance (MR) properties were investigated. The MR in the annealed ribbon was assessed by the magnetic field direction perpendicular to the ribbon surface with the magnetic field up to 30 kOe. The large negative value of 25% for MR was obtained at 244 K. The exchange bias (EB) effects of the as-spun and annealed ribbons were investigated. After annealing, the EB effects have been improved by about 25 Oe at the temperature of 50 K. The magnetizations have increased approximately by 10% more than the as-spun ribbon.

Huang Qingxue;Chen Fenghua;Zhang Mingang;Xu Xiaohong

Chinese Physics B

2016

© 2016 - STC "Institute for Single Crystals". In paper, two rolling bond processes for heavy-gauge steel plate Q235B were studied and the processes were simulated by MARC software. The mechanical properties and microstructure at the interface were comparative analyzed for the two bonded plates using different rolling process. Using MARC software analysis for two rolling process, the ratio of equivalent stress in rolling process /yield stress in current temperature from surface to center portion was relatively uniform for rolling bonded.

Zhao Guanghui;Huang Qingxue;Zhou Cunlong;Zhang Zhanjie;Ma Lifeng;Wang Xiaogang

Functional Materials

2016

© 2016 CSIC. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial (by-nc) Spain 3.0 License. Heavy-gauge Q235 steel plate was roll bonded, and the process was simulated using MARC software. Ultrasonic testing results revealed the presence of cracks and lamination defects in an 80-mm clad steel sheet, especially at the head and tail of the steel plate. There were non-uniform ferrite + pearlite microstructures and unbound areas at a bond interface. Through scanning electron microscopy analysis, long cracks and additional inclusions in the cracks were observed at the interface. A fracture analysis revealed non-uniform inclusions that pervaded the interface. Moreover, MARC simulations demonstrated that there was little equivalent strain at the centre of the slab during the first rolling pass. The equivalent centre increased to 0.5 by the fourth rolling pass. Prior to the final pass, the equivalent strain was not consistent across the thickness direction, preventing bonding interfaces from forming consistent deformation and decreasing the residual stress. The initial rolling reduction rate should not be very small (e.g. 5%) as it is averse to the coordination of rolling deformation. Such rolling processes are averse to the rolling bond.

Zhao Guanghui;Huang Qingxue;Zhou Cunlong;Zhang Zhanjie;Ma Lifeng;Wang Xiaogang

Revista De Metalurgia

2016

© 2017 American Chemical Society. Surface functionalization by alkylsilanes has been widely used in many engineering applications. In this work, a systematic investigation was conducted on the deposition behaviors of octadecyltrichlorosilane (OTCS) on freshly cleaved mica surfaces that possess a low density of reactive sites (i.e., silanol groups) by a vapor-deposition method. The deposition of OTCS molecules on mica was found to follow a two-stage process, as monitored by measuring the surface morphology using an atomic force microscope and wettability of the samples obtained at different deposition times. The contact mechanics behaviors and interaction forces of the as-obtained OTCS surfaces were characterized using a surface forces apparatus. The contact mechanics tests demonstrate that the OTCS coatings can significantly reduce the surface adhesion and adhesion hysteresis in air. The force-distance profiles of the OTCS surfaces obtained via a shorter deposition time (e.g., 2, 8 h) in aqueous solutions could be reasonably described by the classical Derjaguin-Landau-Verwey-Overbeek theory. However, for the OTCS surfaces obtained by longer deposition times (e.g., 48 h), hydrophobic interaction and steric interaction play an important role due to the enhanced surface hydrophobicity and roughness. Our results provide useful insights into the physicochemical characteristics of alkylsilane deposition and the surface interaction mechanisms of deposited alkylsilanes at solid-air and solid-water interfaces.

Huang Jun;Liu Xiaokong;Qiu Xiaoyong;Xie Lei;Yan Bin;Zeng Hongbo;Wang Xiaogang;Huang Qingxue

Journal of Physical Chemistry B

2017