The metal transfer mode of electron beam welding （EBW） with filler wire was studied experimentally. The spatial position between the electron beam and the filler wire was defined. Basing on the charge coupled device...The metal transfer mode of electron beam welding （EBW） with filler wire was studied experimentally. The spatial position between the electron beam and the filler wire was defined. Basing on the charge coupled device （CCD） visual sensing system, the metal transfer mode of filler wire was investigated. The results showed that there were five transfer modes during EBW process due to different wire feed rates and spatial positions between beam and filler wire, such as short-circuiting mode, molten metal bridge mode, small droplet mode, big droplet mode and mixed mode. By comparing the weld appearance of different transfer modes, the molten metal bridge transfer was proved to be the best transfer mode.展开更多
The selection of narrow band filter＇s center wavelength has an important influence on the quality of the weld pool image captured in passive vision mettmd for controlling arc welding process. In this paper, 29 narrow...The selection of narrow band filter＇s center wavelength has an important influence on the quality of the weld pool image captured in passive vision mettmd for controlling arc welding process. In this paper, 29 narrow band filters with different center wavelengths ranging from ultraviolet to near infrared wavelength were used to capture images of weld pool during both the peak current period and the base current period of P-GMA W （ pulsed gas metal arc welding）. The experimental results showed that the filters with near infrared center wavelength could weaken the arc most during the peak current period, while during the base current period the entire weld pool could be seen with the filters with wavelength above 600 nm. The camera spectral response and the radio of arc to weld pool emission were considered to analyze the phenomenon of experimental results.展开更多
Taking the electroslag remelting with pipe electrode(ESR-PE)and electroslag remelting with solid electrode(ESR-SE)as the research objects,a two-dimensional steady-state mathematical model of coupled electromagnetic fi...Taking the electroslag remelting with pipe electrode(ESR-PE)and electroslag remelting with solid electrode(ESR-SE)as the research objects,a two-dimensional steady-state mathematical model of coupled electromagnetic field equation,energy equation,and flow equation was established.The distribution of its current density,Joule heat,flow field,and temperature field was compared and the difference of their molten metal pool was analyzed.The results show that compared with those of ESR-SE,current density distribution and Joule heating area of ESR-PE are mainly concentrated in the inner and outer wall areas of the electrode tip,while the Joule heat generated in the central area of the slag pool is less.In the ESR-PE,the slag flows from the outside of the electrode to the hollow area of the electrode,which makes the temperature distribution in the slag pool is more uniform.Affected by the Joule heating area and flow field,the heat of ESR-SE is concentrated below the electrode in the slag pool area and it transfers from the center to the periphery.However,in the ESR-PE,the heat is concentrated near the inner and outer walls of the electrode tip,and the heat is transferred from the periphery to the center of the slag pool.The molten metal pool depth of ESR-SE is 0.1188 m and that of ESR-PE is 0.0962 m.Compared with that of ESR-SE,the molten metal pool of ESR-PE is shallower and flatter.展开更多
文摘The metal transfer mode of electron beam welding （EBW） with filler wire was studied experimentally. The spatial position between the electron beam and the filler wire was defined. Basing on the charge coupled device （CCD） visual sensing system, the metal transfer mode of filler wire was investigated. The results showed that there were five transfer modes during EBW process due to different wire feed rates and spatial positions between beam and filler wire, such as short-circuiting mode, molten metal bridge mode, small droplet mode, big droplet mode and mixed mode. By comparing the weld appearance of different transfer modes, the molten metal bridge transfer was proved to be the best transfer mode.
基金Acknowledgement The authors are grateful to the financial support for this project from the National Natural Science Foundation of China under grant No. 51005069.
文摘The selection of narrow band filter＇s center wavelength has an important influence on the quality of the weld pool image captured in passive vision mettmd for controlling arc welding process. In this paper, 29 narrow band filters with different center wavelengths ranging from ultraviolet to near infrared wavelength were used to capture images of weld pool during both the peak current period and the base current period of P-GMA W （ pulsed gas metal arc welding）. The experimental results showed that the filters with near infrared center wavelength could weaken the arc most during the peak current period, while during the base current period the entire weld pool could be seen with the filters with wavelength above 600 nm. The camera spectral response and the radio of arc to weld pool emission were considered to analyze the phenomenon of experimental results.
基金The authors gratefully express their appreciation to Natural Science Foundation of China(No.51974153,No.U1960203)the Joint Fund of State key Laboratory of Marine Engineering and University of Science and Technology Liaoning(SKLMEA-USTLN-201901,SKLMEA-USTL-201707)the China Scholarship Council(201908210457).
文摘Taking the electroslag remelting with pipe electrode(ESR-PE)and electroslag remelting with solid electrode(ESR-SE)as the research objects,a two-dimensional steady-state mathematical model of coupled electromagnetic field equation,energy equation,and flow equation was established.The distribution of its current density,Joule heat,flow field,and temperature field was compared and the difference of their molten metal pool was analyzed.The results show that compared with those of ESR-SE,current density distribution and Joule heating area of ESR-PE are mainly concentrated in the inner and outer wall areas of the electrode tip,while the Joule heat generated in the central area of the slag pool is less.In the ESR-PE,the slag flows from the outside of the electrode to the hollow area of the electrode,which makes the temperature distribution in the slag pool is more uniform.Affected by the Joule heating area and flow field,the heat of ESR-SE is concentrated below the electrode in the slag pool area and it transfers from the center to the periphery.However,in the ESR-PE,the heat is concentrated near the inner and outer walls of the electrode tip,and the heat is transferred from the periphery to the center of the slag pool.The molten metal pool depth of ESR-SE is 0.1188 m and that of ESR-PE is 0.0962 m.Compared with that of ESR-SE,the molten metal pool of ESR-PE is shallower and flatter.
