The welding heat source models and the plastic tension zone sizes of a typical weld joint involved in the double floor structure of high speed train under different welding parameters were calculated by a thermal-elas...The welding heat source models and the plastic tension zone sizes of a typical weld joint involved in the double floor structure of high speed train under different welding parameters were calculated by a thermal-elastic-plastic FEM analysis based on SYSWELD code.Then,the welding distortion of floor structure was predicted using a linear elastic FEM and shrinkage method based on Weld Planner software.The effects of welding sequence,clamping configuration and reverse deformation on welding distortion of floor structure were examined numerically.The results indicate that the established elastic FEM model for floor structure is reliable for predicting the distribution of welding distortion in view of the good agreement between the calculated results and the measured distortion for real double floor structure.Compared with the welding sequence,the clamping configuration and the reverse deformation have a significant influence on the welding distortion of floor structure.In the case of30 mm reverse deformation,the maximum deformation can be reduced about 70%in comparison to an actual welding process.展开更多
Effects of the aging temperature on the hardening response, the tensile properties and the precipitate micro- structure evolution of 1460 alloy were studied in this work. It was found that Al3 （Sc, Zr） and δ′ （Al...Effects of the aging temperature on the hardening response, the tensile properties and the precipitate micro- structure evolution of 1460 alloy were studied in this work. It was found that Al3 （Sc, Zr） and δ′ （Al3Li） phases were precipitated from the matrix at the very early aging stage, while the precipitation of T1 （Al2CuLi） and θ′ （Al2Cu） was much slower than that of the δ′ phase. When aging at higher temperature （160 and 190 ℃）, the δ′, T1 and θ′ phases tended to form simultaneously and grow up very quickly. Conversely, the δ′ and θ″ （Al2Cu） phases were precipitated separately and more dispersive at lower aging temperature （130 ℃）. Taken together, the alloy aged at 160 ℃ exhibited improved mechanical properties owing to the uniform dispersion of the fine T1 precipitates.展开更多
基金financial support to this project from the Chinese CSR Qingdao Sifang Co.,Ltd
文摘The welding heat source models and the plastic tension zone sizes of a typical weld joint involved in the double floor structure of high speed train under different welding parameters were calculated by a thermal-elastic-plastic FEM analysis based on SYSWELD code.Then,the welding distortion of floor structure was predicted using a linear elastic FEM and shrinkage method based on Weld Planner software.The effects of welding sequence,clamping configuration and reverse deformation on welding distortion of floor structure were examined numerically.The results indicate that the established elastic FEM model for floor structure is reliable for predicting the distribution of welding distortion in view of the good agreement between the calculated results and the measured distortion for real double floor structure.Compared with the welding sequence,the clamping configuration and the reverse deformation have a significant influence on the welding distortion of floor structure.In the case of30 mm reverse deformation,the maximum deformation can be reduced about 70%in comparison to an actual welding process.
文摘Effects of the aging temperature on the hardening response, the tensile properties and the precipitate micro- structure evolution of 1460 alloy were studied in this work. It was found that Al3 （Sc, Zr） and δ′ （Al3Li） phases were precipitated from the matrix at the very early aging stage, while the precipitation of T1 （Al2CuLi） and θ′ （Al2Cu） was much slower than that of the δ′ phase. When aging at higher temperature （160 and 190 ℃）, the δ′, T1 and θ′ phases tended to form simultaneously and grow up very quickly. Conversely, the δ′ and θ″ （Al2Cu） phases were precipitated separately and more dispersive at lower aging temperature （130 ℃）. Taken together, the alloy aged at 160 ℃ exhibited improved mechanical properties owing to the uniform dispersion of the fine T1 precipitates.
