D.Q. Li
,
D. Li
,
L.H. Nan and X.T. Tian National Key Laboratory of Advanced Welding Production Technology
,
HIT
,
Harbin 150001
,
China
金属学报(英文版)
In order to effectively control the stress and distortion which produced in welding process, the dynamic change laws of displacement field is the most important factor. The characteristics of the welding dynamic displacement field is high temperature, high strain velocity, thus ordinary methods such as resistance strain gauge or Moiré method can not be used for the measurement of the zone of high temperature. Speckle interference method has the merits of non-contact, resistance to the disturbance of impure lights, high accuracy of measurement (half of wavelength).The paper represents the measurement of dynamic displacement field of argon-arcspot welding, by which it shows that the method of speckle interference is feasible for the measurement of welding dynamic displacement.
关键词:
welding dynamic displacement field
,
null
,
null
C.G.Shi
,
Y.H.Wang
,
L.G.Cai
,
C.H.Zhou
金属学报(英文版)
There are four new achievements of this work on the theory and technology of explosive welding.(1) It has been found and defined three kinds of bonding interfaces: big wavy, small wavy and micro wavy, and the micro wavy interface is the best. In a cladding plate,it is for the first time to find that the form of interface presents regular distribution.(2) Although the interface has the features of melt, diffusion and pressure welding in the mean time, the seam and "hole" brought by the melt weaken the bonding strength of interface greatly, and the effect of melt on interface must be eliminated in explosive welding, so explosive welding is not a melt weld. The diffusion welding is a kind of form of pressure welding, and the diffusion is not the reason of the bonding of interface but the result of interface high pressure. So the diffusion welding cannot also explain the bonding mechanism of it. The experiment and theory make clear that explosive welding is a special pressure one.(3) To get good interface of no melt, explosive charge must be selected on the low limit of welding windows. In explosive welding, the drive plate should be treated as the viscous and plastoelastic body, not incompressible fluid. The bending moment under the explosive welding loading must be greater than that under dynamic limit of drive plate. According to the condition, the lower limit of explosive welding is obtained. It is about 20 1.019373e-312ss than that obtained by tradition calculation, and suitable for engineering application.(3) It is for the first time to test and study on soil anvil characteristics and change regularity under explosive welding impact loading. Through soil anvil parameter optimization analysis, it is the best for explosive welding with sandy soil of water content 17.00and density 1.74g/cm^3.
关键词:
explosive welding
,
null
,
null
H. Y. Zhao
,
A. L. Lu
,
Q. Y. Shi and F. Yan (Welding Division
,
Department of Mechanical Engineering
,
Tsinghua University
,
Beijing 100084
,
China)
金属学报(英文版)
T-joints are widely used in ship manufacturing and other welding structures.The welding residual stress and deformation hare significant influence on failure and service life in welding structures.By us- ing of 3D thermal elasto - plastic FEM, the temperature fields,stress fields and deformation of weld- ing processes on T - joints are analyzed in this paper.The moving heat source is considered in the com- putation. Moreover, weld metal filling and multiple - pass welding are simulated using activate/deac- tivate ability.For avoiding "locking" in full integration elements of welding computation,the re- duced intergration elements are used in weld area.The nonlinear FEM analysis program MARC is used to complete the computations, as well as its user subroutines that are programmed to develop the special techniques needed in the simulation of welding process.Some different welding procedures are com- pared, and the welding residual stress and deformation are discussed in details.
关键词:
welding
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null
,
null
,
null
,
null
Zhihua LIU
,
Qing ZHAO
,
Deqing LI
材料科学技术（英文）
In this paper, technology margin experiment of hollow cathode fusion are welding (FAW) and penetrating are welding (PAW) is presented in detail. The advantages of PAW, compared with FAW, are better weld formation, narrower welds, as well as a larger welding technology margin. Technological experiment and hydraulic test for the Ti alloy pressure vessels with PAW are described. Also, the weld formation control on Ti alloys is preliminarily analyzed. Finally, conclusions are addressed.
关键词:
聂鸳鸳
,
段继周
,
杜敏
,
侯保荣
中国腐蚀与防护学报
doi:10.11902/1005.4537.2013.160
利用荧光显微观察技术选择临界使用浓度的NaN3,分别在O2及N2气氛下采用循环伏安及电化学阻抗技术研究其氧还原过程的电化学行为.结果表明,不锈钢表面的生物膜能够加大还原峰电流密度值,当使用临界浓度的NaN3处理不锈钢试样后,还原峰值明显减小,且峰电位均负移.微生物膜能够促进电子传递给最终电子受体O2,同时降低不锈钢材料发生腐蚀的可能性.由此推测,天然海水中,316L不锈钢表面微生物膜改变了传统阴极氧还原的电子传递途径,即加速了O2作为最终电子受体的电子传递过程,催化了O2的还原;同时,还能够抑制不锈钢材料的腐蚀.
关键词:
天然海水
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316L不锈钢
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NaN3
,
微生物膜
,
细胞色素c氧化酶
,
氧还原
ZHANG Yunhua
,
GAN Fuxing
,
LI Meng
,
WANG Dihua
,
HUANG Zhongmai
,
GAO Yunpeng
钢铁研究学报(英文版)
Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant of WISCO [Wuhan Iron and Steel (Group) Corporation]. The results of the onsite industrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580-780 μS/cm to 100-350 μS/cm. The average removal efficiency of Cl- and Ca2+ was about 75% and 68%, respectively, and CODCr of the treated water was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 06 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel electrosorption technology can be used in enhanced desalination and purification treatment of reused comprehensive wastewater in iron and steel industry.
关键词:
electrosorption
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desalination
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purification
,
conductivity
,
industrial reused water
Keke ZHANG
,
Yunlin YANG
,
Changsheng WANG
,
Hongke LI
,
Jin XUE
材料科学技术（英文）
The microstructure of 40Cr and T10A steel sample and its surface to be welded is ultra-fined through salt-bath cyclic quenching and high frequency hardening, then the surface is cleaned. Under non-vacuum and no shielded gas, the welding parameter of isothermal superplastic solid-phase welding and the effect of surface microstructure prior to pressure welding on the quality of joint are stud led. At the temperature of 730 similar to 750 ℃ and at initial strain rate of (2～4) x 10(-4) s(-1) the strength of the joint is up to or close to that of 40Cr base metal in 3 similar to5 min pressure welding.
关键词:
Peng HE
,
Jicai FENG
,
Jiecai HAN
,
Yiyu QIAN
材料科学技术（英文）
A fundamental theory for the analysis of residual welding stresses and deformation based on the inherent strain distribution along the welded joint is introduced. The method of predicting maximum hardness Hv(y, z) and maximum inherent strain gmax is given. The model T.E.P-Tav-hardness calculation is proposed to predict distribution of inherent strains in T type welding structure. By T.E.P-Tav-hardness calculation, distribution of longitudinal inherent strains can be predicted in T type welding structure, and calculation and experimental results are consistent.
关键词:
Inherent strain
,
null
,
null
Journal of Alloys and Compounds
As hydrogen, deuterium and tritium storage materials, a series of investigations of mechanical and thermal properties of titanium hydrides, deuterides and tritides have been performed, however, very limited theoretical studies of thermodynamic properties for them can be found. Based on density-functional theory (DFT) and density-functional perturbation theory (DFPT) we have discussed systematically the hydrogen isotope effects on the thermodynamic properties of TiX2 (X = H, D, and T) system. Our calculations indicate that for evaluating accurately their physical properties at absolute zero temperature, such as the equilibrium lattice constants, bulk modulus, and heat of formation, the zero-point energy correction must be taken into account. By performing the phonon calculation within quasiharmonic approximation (QHA), we obtain their vibrational free energies, vibrational entropies, and temperature dependence of specific heat, thermal expansion, and bulk modulus. Those results demonstrate that comparing with TiH2, TiT2 and TiD2 are more stable and the zero-point effects play an important role in their thermal expansion. The increase in the force constant between Ti and H causes the higher value of specific heat of TiH2 during the phase transition from FCC to FCT. In addition, comparing with available experimental values, we can conclude that QHA is feasible for describing the thermal properties of TiX2. (C) 2006 Elsevier B.V. All rights reserved.
关键词:
isotope effects;thermodynamic properties;density-functional;perturbation theory;quasiharmonic approximation;functional perturbation-theory;neutron spectroscopy;thermal-properties;titanium;hydrogen;dependence;expansion;constants;palladium;hydrides
Yajiang LI
,
Bing ZHOU
,
Tao FENG
,
Jiangwei REN
材料科学技术（英文）
Microstructure performance in the welding zone of T91 heat-resistant steel under the condition of TIG welding was researched by means of metallography, X-ray diffraction and scanning electron microscope (SEM).Experimental results indicated that microstructure of T91 weld metal was austenite + a little amount of d ferrite when using TGS-9cb filler wire.Substructure inside the austenite grain was crypto-crystal lath martensite, on which some Cr23C6 blocky carbides were distributed. The maximum hardness (HRC44) in the welding zone is near the fusion zone. There existed no obvious softening zone in the heat-affected zone (HAZ). For T91 steel tube of F63 mm×5 mm, when increasing welding heat input (E) from 4.8 kJ/cm to 12.5 kJ/cm, fracture morphology in the fusion zone and the HAZ changed from dimple fracture into quasi-cleavage fracture (QC). Controlling the welding heat input of about 9.8 kJ/cm is suitable in the welding of T91 heat-resistant steel.
关键词:
T91 heat-resistant steel
,
null
,
null
