2021年, 第30卷, 第2期 
刊出日期:2021-06-28
  

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  • 郭伟, 蔡艳
    中国焊接. 2021, 30(2): 1-10. https://doi.org/10.12073/j.cw.20210212003
    摘要 ( ) PDF全文 ( )   可视化   收藏
    Equiatomic CrMnFeCoNi high entropy alloy prepared by powder metallurgy was remelted by laser. The relative density and microstructure of fusion zone are evaluated. The nanoindentation tests are conducted to reveal the hardness difference of dendrite arms and interdendritic areas. Tensile tests are conducted to assess the mechanical properties of remelted HEA. After laser remelting, the number and morphology of voids changed significantly. Dendritic structure with face-centered cubic phase form in the fusion zone. Fe, Cr and Co are enriched in dendrite arm, while Mn and Ni are enriched in interdendritic area. Elements segregation led to a nanohardness difference between dendrite arm and interdendritic area. Local deformation occurs in interdendritic area during tensile tests and results in a fracture with directionality.
  • 祁俊翔, 缪广红, 艾九英, 胡昱
    中国焊接. 2021, 30(2): 11-16. https://doi.org/10.12073/j.cw.20210222001
    摘要 ( ) PDF全文 ( )   可视化   收藏
    In order to guide the explosive welding experiment of titanium-stainless steel, Three-dimensional numerical simulation of explosive welding, which select TA1 as flyer plate and 304 stainless steel as base plate, is carried out by using the LS-DYNA software and SPH-FEM coupling algorithm in the present study. The explosive welding window is calculated and established. It is found that the numerical simulation results are in good agreement with the experimental results. The displacement, velocity and pressure-time curves of characteristic elements show that the quality of explosive welding composites is superior. It is proved that SPH-FEM coupling algorithm is effective for explosive welding of TA1 / 304 stainless steel and can effectively guide the selection of explosive welding parameters.
  • 赵鹏康, 方魁, 唐成, 牛建平, 郭美玲
    中国焊接. 2021, 30(2): 17-24. https://doi.org/10.12073/j.cw.20210303001
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    In the paper, the finite element model (FEM) of wire arc additive manufacturing (WAAM) by TIG method was established by the ABAQUS soft, and the phase transformation latent heat was considered in the model. The evolution rules of temperature field at the interlayer with the cooling time of 10 s, 30 s and 50 s were obtained by the model. The WAAM experiment were performed by 5356 aluminum alloy welding wire with $\phi $1.2 mm, and the simulated temperature field were varified by the thermocouple. The result shows that the highest temperature at the molten pool center increases with the increased interlayers at the same interlayer cooling time; the highest temperature drops gradually and the decline is smaller with the increased interlayer cooling time at the same layer. No remelting occurs at the top layer, and at least two remelting times occur in the other layers, resulting in complex temperature field evolution.
  • 江吉彬, 周井鑫, 陈昌荣, 俞希伟, 练国富, 高险峰
    中国焊接. 2021, 30(2): 25-34. https://doi.org/10.12073/j.cw.20210206003
    摘要 ( ) PDF全文 ( )   可视化   收藏
    Weld bead morphology plays an important role in welding procedure specification and welding process planning. In order to obtain the quantitative relationship between process parameters and weld morphology of DH36 marine steel plate, grey correlation method was used to study multiple morphology characteristics simultaneously. Eighteen experimental runs were proposed according to orthogonal method. With grey correlation theory, three response objectives, aspect ratio, depth of penetration and weld were transformed into a single grey correlation grade (GRG). The process parameters were quantitatively correlated to the GRG value and optimized with the target of maximum aspect ratio, minimum depth of penetration and maximum weld area. The results show that the optimized weld bead morphology is better than other weld bead morphology. The relative error of the predicted GRG with respect to the actual value is 5.06%, which further verifies the accuracy of the established model. The microstructure and hardness analysis suggests that the optimized welded joint has obtained required mechanical properties.The research outcomes provide a theoretical basis for multi-objective optimization of arc welding morphology in practical applications.
  • 刘均波, 王立梅, 刘均海
    中国焊接. 2021, 30(2): 35-41. https://doi.org/10.12073/j.cw.20210320001
    摘要 ( ) PDF全文 ( )   可视化   收藏
    A certain amount of Ti was added to the plasma cladding Fe-Cr-C coating in the early stage in order to improve the quality and properties of the coating. Ti-Fe-Cr-C composite powder was prepared by precursor carbonization-composition process. In situ synthesized TiC-Fe-Cr coatings were fabricated on substrate of Q235 steel by plasma cladding process with the composite powder. Microstructures of the coatings with different process parameters, including cladding current, cladding speed, number of overlapping cladding layers, were analyzed by scanning electron microscope. The results show that the structure of the TiC-Fe-Cr coating is greatly affected by the cladding current, the cladding speed and the overlapping cladding process. In this test, when the cladding current of 300 A and the cladding process parameter of the cladding speed of 50 mm/min are clad with three layers, a well-formed and well-structured TiC-Fe-Cr coating can be obtained in this test. TiC-Fe-Cr coating has good wear resistance and good load characteristics under dry sliding wear test conditions.
  • 李军, 温树文, 方敏杰, 张书彦, 路浩
    中国焊接. 2021, 30(2): 42-49. https://doi.org/10.12073/j.cw.20210303002
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    The residual deformation in thin-plate butt weldments without wire filling was investigated by simulative and experimental methods. The good consistency on the residual deformation between the simulation result and test measurement data indicates that the contact mode can be used to simulate the butt welding process of thin plates without wire filling. The longitudinal residual tensile stress in the weld zone lead to the buckling deformation of thin-plate weldments, and the appearance of buckling deformation would in turn reduce the peak value of longitudinal residual tensile stress. As for the thin-plate butt weldments, the tensile stresses in the weld and its neighboring zone are produced in the post-weld cooling process and have not peak until the temperature of the welds dropped to near room temperature.
  • 王月, 柴鹏, 郭晓娟, 齐铂金
    中国焊接. 2021, 30(2): 50-57. https://doi.org/10.12073/j.cw.20200917001
    摘要 ( ) PDF全文 ( )   可视化   收藏
    The static and fatigue properties of 7B04 aluminum alloy structures connected by riveting and refill friction stir spot welding (refill FSSW) were compared and analyzed. Results show that the static compression load of the typical structure connected by riveting and refill FSSW fluctuated in the range of 117–124 kN, and the shear load was in the range of 89–95 kN. Welds spacing had a small influence on the static load of the structures joined by refill FSSW. However, the fatigue life of riveted structures was lower than that joined by refill FSSW. For the welded structure, the heterogeneous microstructures of the welded joint led to the uneven microhardness, and the hook at the lap interface bent upwards at the same time. These factors made the welded structures during the fatigue test failure along the path of sleeve moving.
  • 伍文勇, 杨智, 岳双成
    中国焊接. 2021, 30(2): 58-66. https://doi.org/10.12073/j.cw.20210321001
    摘要 ( ) PDF全文 ( )   可视化   收藏
    The present paper investigates the welding forming, microstructure and shear tensile test of lap joints with large thickness ratio which were fabricated by laser screw welding (LSW) and resistant spot welding (RSW). The comparison was conducted on two kinds of lap joints, galvanized sheet and hot pressed steel (GS-HPS), galvanized sheet and high strength steel (GS-HS). The microstructure and fracture morphology were analyzed by optical microscope. It was demonstrated that with large thickness ratio the sound lap joint of GS-HS could be obtained by LSW regardless of the irradiation of laser beam from thick metal to sheet or otherwise, and the morphology shows it is better when the laser is irradiated on the thick metal. Nevertheless, when the laser beam was applied on thick metal of HPS, blind hole or blowhole was formed in the center of joint, which is attributed to the shrinkage during solidification of the molten pool. Small pores or dispersed porosity appeared on the faying face of the joint without predetermined gap which provides the degassing. However, the increase of predetermined gap could reduce the shear strength and nugget size. Two kinds of joints made by LSW have superior shear strength than those made by RSW when the laser were applied on galvanized sheet.