This paper describes a way to improve the weld quality through suppressing the porosity formation and restraining the growth of columnar grains by using a weaving beam in laser welding. The experimental results show t...This paper describes a way to improve the weld quality through suppressing the porosity formation and restraining the growth of columnar grains by using a weaving beam in laser welding. The experimental results show that the N2 porosity of beam-weaving laser welding low carbon steel can be remarkably reduced with increasing weaving frequency, and porosity can be eliminated when the weaving amplitude is only 0.5 mm; and the Ar porosity in the weld metal is decreased with increasing weaving frequency and amplitude when the welding speed is higher than 0.5 m/min. The beam-weaving laser welding of ultra-fine grained steel has been investigated. The experimental results show that beam-weaving laser welding with appropriate amplitude and frequency can partly restrain the growth of the columnar grain and improve the tensile strength of the weld metal.展开更多
Electron beam welding experiment of titanium alloy to chromium bronze with a vanadium filler metal was carried out. Microstructure of the joint was observed by optical microscopy and scanning electron microscopy. Tens...Electron beam welding experiment of titanium alloy to chromium bronze with a vanadium filler metal was carried out. Microstructure of the joint was observed by optical microscopy and scanning electron microscopy. Tensile strength of the joint was evaluated. The fracture surface of the joint was also analyzed. The results showed that the addition of vanadium filler metal reduced the brittleness of joint by increasing the amount of vanadium-based solid solution in the weld. But the melting point of vanadium.filler metal was so high that large heat input was needed to completely melt the filler metal. Thus, a large amount of interfacial compounds were produced. The tensile strength of joint was 280 MPa with a brittle fracture mode.展开更多
基金The research was supported by the National Natural Science Foundation of China(NSFC No.50175061)the 973 Science and Technology Development Plan of the Basic Research Foundation of China(No.1998061500).
文摘This paper describes a way to improve the weld quality through suppressing the porosity formation and restraining the growth of columnar grains by using a weaving beam in laser welding. The experimental results show that the N2 porosity of beam-weaving laser welding low carbon steel can be remarkably reduced with increasing weaving frequency, and porosity can be eliminated when the weaving amplitude is only 0.5 mm; and the Ar porosity in the weld metal is decreased with increasing weaving frequency and amplitude when the welding speed is higher than 0.5 m/min. The beam-weaving laser welding of ultra-fine grained steel has been investigated. The experimental results show that beam-weaving laser welding with appropriate amplitude and frequency can partly restrain the growth of the columnar grain and improve the tensile strength of the weld metal.
文摘Electron beam welding experiment of titanium alloy to chromium bronze with a vanadium filler metal was carried out. Microstructure of the joint was observed by optical microscopy and scanning electron microscopy. Tensile strength of the joint was evaluated. The fracture surface of the joint was also analyzed. The results showed that the addition of vanadium filler metal reduced the brittleness of joint by increasing the amount of vanadium-based solid solution in the weld. But the melting point of vanadium.filler metal was so high that large heat input was needed to completely melt the filler metal. Thus, a large amount of interfacial compounds were produced. The tensile strength of joint was 280 MPa with a brittle fracture mode.
