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激光表面处理对马氏体不锈钢堆焊层组织与性能的影响

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金属热处理 2024年第3期49卷 56-63页

作者：邓德伟李振华陈文博汪红所孙磊大连理工大学材料科学与工程学院辽宁省激光3D打印装备及应用专业技术创新中心辽宁大连116024 大连船用阀门有限公司辽宁大连116026

为有效修复FV520B钢表面损伤,并提升修复后表面的耐腐蚀性能,尝试采用先堆焊,再进行激光表面处理的方法,即先采用明弧摆动堆焊方法,在FV520B钢基材上使用马氏体型药芯焊丝进行堆焊,并分别采用两种激光(半导体激光和光纤激光)对堆焊后的... 详细信息

为有效修复FV520B钢表面损伤,并提升修复后表面的耐腐蚀性能,尝试采用先堆焊,再进行激光表面处理的方法,即先采用明弧摆动堆焊方法,在FV520B钢基材上使用马氏体型药芯焊丝进行堆焊,并分别采用两种激光(半导体激光和光纤激光)对堆焊后的表面进行激光表面处理。研究了堆焊层的显微组织、硬度,堆焊层与基材的元素分布情况,以及经过激光表面处理后堆焊层的显微组织、硬度、耐腐蚀性和激光作用深度。研究结果表明,堆焊层由马氏体、δ-铁素体、残留奥氏体和碳化物构成,硬度约为480 HV0.3,相比基材提高了约33.33%,堆焊层与基材之间冶金结合良好。经过激光表面处理后,堆焊层分为原始堆焊区、热影响区和重熔区。在热影响区,硬度会下降,这与激光表面处理的回火作用有关;在重熔区,硬度与原始焊接区相当。浸泡试验结果表明,激光表面处理提高了堆焊层的耐腐蚀性。随着扫描速度的降低,激光的作用深度会增加,但硬度变化不大。相对于光纤激光器,半导体激光器的作用深度更大,但两种激光处理后的表面硬度基本相同。

关键词： FV520B钢堆焊激光表面处理组织硬度

FV520B钢表面熔化极气体保护焊堆焊层及其激光淬火后的组织与性能

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机械工程材料 2024年第5期48卷 105-110页

作者：邓德伟孟凡民汪红所陈文博孙磊大连理工大学材料科学与工程学院辽宁省激光3D打印装备及应用专业技术创新中心大连116024 大连船用阀门有限公司大连116026

采用熔化极气体保护焊在FV520B钢板上进行单层单道、二层多道以及三层多道同质堆焊试验,并对单层单道堆焊层进行激光淬火处理,研究了不同堆焊层和激光淬火后堆焊层的显微组织、硬度和耐腐蚀性能。结果表明:堆焊层由板条状马氏体、少量... 详细信息

采用熔化极气体保护焊在FV520B钢板上进行单层单道、二层多道以及三层多道同质堆焊试验,并对单层单道堆焊层进行激光淬火处理,研究了不同堆焊层和激光淬火后堆焊层的显微组织、硬度和耐腐蚀性能。结果表明:堆焊层由板条状马氏体、少量δ铁素体和一些碳化物组成,显微硬度为350 HV,与母材相比提高了14.7%,层间和道间交界处的组织中δ铁素体减少,最高硬度分别为380.3,373.5 HV,相对于堆焊层提高了8.0%,6.7%左右;堆焊层的腐蚀速率低于母材,且随着堆焊层数的增加,腐蚀速率不变。激光淬火后堆焊层的马氏体组织更加细小,淬火区和热影响区的厚度分别为194.3,186.3μm,堆焊层的最高硬度提高至390.4 HV;随着距淬火表面距离的增大,硬度先升高后降低;激光淬火后堆焊层的腐蚀速率比未进行激光淬火的堆焊层低。

关键词： FV520B钢同质堆焊激光淬火组织硬度耐腐蚀性能

Influence of post-weld heat treatment on microstructure and properties in heat-affected zone of KMN steel joint

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China Welding 2014年第2期23卷 1-6页

作者： Hao Xiaohu Dong Honggang deng dewei School of Materials and Engineering Dalian University of Technology Dalian116024

The influence of temperature during post-weld heat treatment on the microstructure and properties of KMN steel joints was investigated. The results reveal that after heat treatment, the martensite transformed to tempered sorbite, causing the softening of the resultant joints. XRD test shows that the residual austenite content decreased obviously when the joint was heattreated at 550 ℃ and 580 ℃, which degraded the impact toughness of heat-affected zone （ HAZ）. When the heat treatment temperature increased further, the dispersion strengthening from the precipitation of alloying elements improved the impact toughness of HAZ. The aggregation and coarsening of carbide also contributed to the improvement of impact toughness of HAZ.

关键词： KMN steel post-weld heat treatment microstructure hardness impact toughness

CuTiNiZrV Amorphous Alloy Foils for Vacuum Brazing of TiAl Alloy to 40Cr Steel

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Journal of Materials Science & Technology 2015年第2期31卷 217-222页

作者： Honggang Dong Zhonglin Yang Zengrui Wang dewei deng Chuang Dong School of Materials Science and Engineering Dalian University of Technology State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Key Lab of Materials Modi fi cation (Dalian University of Technology) Ministry of Education

Vacuum brazing of TiAl alloy to 40Cr steel sheets was conducted with newly developed CuTiNiZrV amorphous foils. It was found that a diffusion layer,filler metal and reaction layer existed in the brazed seam. The diffusion layer in the joint brazed with Cu43.75Ti37.5Ni6.25Zr6.25V6.25(at.%) foil was flat and thin,containing Ti19Al6 and Ti2Cu intermetallic compounds; however,the diffusion layer brazed with Cu37.5Ti25Ni12.5Zr12.5V12.5 foil was uneven with bulges,consisting of essentially Ti-based solute solution. The foil with 12.5 at.% V showed inferior spreadability compared to that with 6.25 at.% V at brazing temperature. However,fracture happened along the diffusion layer with 6.25 at.% V foil due to the formation of brittle intermetallic phases,but the joints brazed with 12.5 at.% V foil failed through the TiAl substrate. These results show that designing amorphous alloy with less Ti and more V for brazing TiAl alloy to steel is appropriate.

关键词： Titanium aluminide Steel Dissimilar metal joining

Numerical Calculation and Experimental Research on Crack Arrest by Detour Effect and Joule Heating of High Pulsed Current in Remanufacturing

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Chinese Journal of Mechanical Engineering 2014年第4期27卷 745-753页

作者： YU Jing ZHANG Hongchao deng dewei HAO Shengzhi IQBAL Asif Institute of Sustainable Design and Manufacture Dalian University of Technology School of Materials Science and Engineering Dalian University of Technology Key Laboratory of Materials Modification by Laser Ion and Electron Beams of Ministry of EducationDalian University of Technology

The remanufacturing blanks with cracks were considered as irreparable. With utilization of detour effect and Joule heating of pulsed current, a technique to arrest the crack in martensitic stainless steel FV520B is developed. According to finite element theory, the finite element（FE） model of the cracked rectangular specimen is established firstly. Then, based on electro-thermo-structure coupled theory, the distributions of current density, temperature field, and stress field are calculated for the instant of energizing. Furthermore, the simulation results are verified by some corresponding experiments performed on high pulsed current discharge device of type HCPD-I. Morphology and microstructure around the crack tip before and after electro pulsing treatment are observed by optical microscope（OM） and scanning electron microscope（SEM）, and then the diameters of fusion zone and heat affected zone（HAZ） are measured in order to contrast with numerical calculation results. Element distribution, nano-indentation hardness and residual stress in the vicinity of the crack tip are surveyed by energy dispersive spectrometer（EDS）, scanning probe microscopy（SPM） and X-ray stress gauge, respectively. The results show that the obvious partition and refined grain around the crack tip can be observed due to the violent temperature change. The contents of carbon and oxygen in fusion zone and HAZ are higher than those in matrix, and however the hardness around the crack tip decreases. Large residual compressive stress is induced in the vicinity of the crack tip and it has the same order of magnitude for measured results and numerical calculation results that is 100 MPa. The relational curves between discharge energies and diameters of the fusion zone and HAZ are obtained by experiments. The difference of diameter of fusion zone between measured and calculated results is less than 18.3%. Numerical calculation is very useful to define the experimental parameters. An effective method to

关键词： remanufacturing crack arrest numerical simulation microstructure high pulse current

Effect of Post-weld Heat Treatment on Properties of Friction Welded Joint Between TC4 Titanium Alloy and 40Cr Steel Rods

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Journal of Materials Science & Technology 2015年第9期31卷 962-968页

作者： Honggang Dong Lianzhen Yu dewei deng Wenlong Zhou Chuang Dong School of Materials Science and Engineering Dalian University of Technology State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Key Lab of Materials Modification (Dalian University of Technology) Ministry of Education

Dissimilar metal joining of Ti-6AI-4V （TC4） titanium alloy to as-rolled 40Cr steel rods was conducted with friction welding, and the effect of post-weld heat treatment （PWHT） on the microstructure and mechanical properties of the resultant joints was investigated. The average tensile strength of the as-welded joints reached 766 MPa and failure occurred in 40Cr steel base metal. However, after PWHT at 600℃ for 0.5, 1, 2 and 3 h, the tensile strength of the joints decreased and fracture happened through the interface with quasi-cleavage features. The bending angle of specimens was improved from 9.6° in as-welded state to 32.5° after PWHT for 2 h. The tensile strength of the joint was enhanced by martensitic transformation near the interface in as-welded state. Sorbite formed near the interface in PWHT state and improved the bending ductility of the joint. TiC brittle phase formed at the interface after PWHT for 0.5 h and deteriorated the tensile strength and bending ductility of the joint. After PWHT for 2 h, no TiC phase was detected at the interface. The microhardness on the interface in as-welded state was higher than that after PWHT, indicating that the decrease of microhardness around the interface could be accompanied by degradation of tensile strength but improvement of bending ductility of the joints.

关键词： Dissimilar metal joiningFriction weldingTitaniumSteelPost-weld heat treatmentlntermetallic

Continuous high-efficient water-electricity cogeneration over a hybrid solar-driven water evaporation system and the working mechanism

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Science China Materials 2024年第7期67卷 2371-2372页

作者： dewei Chu School of Materials Science and Engineering University of New South WalesSydneyNSW 2052Australia

With the escalation of industrialization and population growth,energy and clean water shortages pose an unprecedented threat to sustainable ***,it is imperative to develop green and effective strategies to address these *** this context,solar-driven interfacial water evaporation(SIWE)has emerged as a highly promising low-carbon solution to the water-energy nexus[1].By locating the evaporator at airwater interfaces,heat localization can be achieved,leading to high-efficient water evaporation and freshwater *** significantly,taking advantage of the special conditions during SIWE has opened numerous opportunities for generation of extra electrical power[2,3].Throughout the processes of SIWE,various elements such as photons,waves,capillary flow,evaporation,vapor motions,condensation,and droplet sliding can all be harnessed to produce electricity through photovoltaic,thermoelectric,thermogalvanic,pyroelectric,piezoelectric,triboelectricity and hydrovoltaic effects[3].Extensive research efforts have provided valuable insights for the development of water-electricity cogeneration(WEG)hybrid systems.

关键词： mechanism evaporation piezoelectric

Doped Amorphous Carbon Films Prepared by Liquid Phase Electrodeposition

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Open Journal of Synthesis Theory and Applications 2014年第1期3卷 5-13页

作者： Canyan Che Yang Li Guifeng Zhang dewei deng Key Laboratory for Materials Modification by Laser Ion and Electron Beams Ministry of Education School of Materials Science and Engineering Dalian University of Technology Dalian China

It has theoretical significance and practical value to synthetize and modify amorphous carbon films by liquid electro-deposition technique due to its low cost, simple equipment, and better operability in uniform deposition of the films with large-area and complex shape work pieces. This article introduces the research situation of the carbon films prepared by liquid phase electrochemical deposition according to the applied voltage, discusses the influence of experimental parameters on the film properties, and describes possible reaction mechanisms. It summarizes the research progress of amorphous carbon films doped with metal and nonmetals. Finally, existing problems have been demonstrated and suggestions on research hotspots in the future are given.

关键词： Liquid Electrodeposition Doping Carbon Films

Self-aligned dual-beam superresolution laser direct writing with a polarization-engineered depletion beam

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Photonics Research 2024年第6期12卷 1194-1200页

作者： GUOLIANG CHEN dewei MO JIAN CHEN QIWEN ZHAN School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Modern Optical System University of Shanghai for Science and TechnologyShanghai 200093China Zhangjiang Laboratory Shanghai 201204China

A fiber-based,self-aligned dual-beam laser direct writing system with a polarization-engineered depletion beam is designed,constructed,and *** system employs a vortex fiber to generate a donut-shaped,cylindrically polarized depletion beam while simultaneously allowing the fundamental mode excitation beam to pass *** results in a co-axially self-aligned dual-beam source,enhancing stability and mitigating assembly *** size of the central dark spot of the focused cylindrical vector depletion beam can be easily adjusted using a simple polarization rotation *** a depletion wavelength of 532 nm and an excitation wavelength of800 nm,the dual-beam laser direct writing system has demonstrated a single linewidth of 63 nm and a minimum line spacing of 173 *** optimization of this system may pave the way for practical superresolution photolithography that surpasses the diffraction limit.

关键词： polarization beam depletion