All position MAG welding is widely applied in pipeline processing. Whereas, welding defects easily happen when welding current is beyond 200 A. In this paper, the force equilibrium condition and influence mechanism of...All position MAG welding is widely applied in pipeline processing. Whereas, welding defects easily happen when welding current is beyond 200 A. In this paper, the force equilibrium condition and influence mechanism of weld pool instability were discussed. Using the hysteresis tension theory on liquid interface, the radial and tangential force imposing on weld pool was analyzed to obtain the mechanical instability criterion on weld pool formation. The criterion provides a good explanation for those corresponding measures promoting weld pool formation in practice.展开更多
In recent years, the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has f...In recent years, the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has firstly developed pipeline laser-arc hybrid welding system in China, and executed the welding tests based on X70/X80 steel. Preliminary experiment results showed that hybrid welding could meet the requirements of related standards such as API1104,ASME,etc., the mechanical properties of girth seam are qualified in the case that there were no internal defects. With the development of high-power fiber laser and the continuous improvement of welding equipment, laser-arc hybrid welding technology for pipeline field welding will be available soon.展开更多
A full automatic welding machine for spherical tanks' all position multi layer welds has been developed. This machine is mainly composed of a two dimension seam tracking system based on microcomputer's memor...A full automatic welding machine for spherical tanks' all position multi layer welds has been developed. This machine is mainly composed of a two dimension seam tracking system based on microcomputer's memory and a welding tractor as well as rail. The main features of the machine are: while welding the first layer of a seam, its microcomputer system can analyze and store the tracing information from a two dimension sensor, and control the welding head device to realize two dimension real time tracing; while welding the second layer up to the top layer of the seam, it can realize two dimension tracing based on the memorial data, automatically determine the layer number and continually sway the welding head. The welding test shows that the machine has good tracing and welding behavior, and is suitable for spherical tank's all position multi layer welds.展开更多
基金Supported by the National Natural Science Foundation of China （ No. 51075299）, Natural Science Foundation of Tianjin （ No. 10JCZDJC23500） and Key Technologies R＆D Program of Tianjin （No. 10ZCKFGX03900）.
文摘All position MAG welding is widely applied in pipeline processing. Whereas, welding defects easily happen when welding current is beyond 200 A. In this paper, the force equilibrium condition and influence mechanism of weld pool instability were discussed. Using the hysteresis tension theory on liquid interface, the radial and tangential force imposing on weld pool was analyzed to obtain the mechanical instability criterion on weld pool formation. The criterion provides a good explanation for those corresponding measures promoting weld pool formation in practice.
文摘In recent years, the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has firstly developed pipeline laser-arc hybrid welding system in China, and executed the welding tests based on X70/X80 steel. Preliminary experiment results showed that hybrid welding could meet the requirements of related standards such as API1104,ASME,etc., the mechanical properties of girth seam are qualified in the case that there were no internal defects. With the development of high-power fiber laser and the continuous improvement of welding equipment, laser-arc hybrid welding technology for pipeline field welding will be available soon.
文摘A full automatic welding machine for spherical tanks' all position multi layer welds has been developed. This machine is mainly composed of a two dimension seam tracking system based on microcomputer's memory and a welding tractor as well as rail. The main features of the machine are: while welding the first layer of a seam, its microcomputer system can analyze and store the tracing information from a two dimension sensor, and control the welding head device to realize two dimension real time tracing; while welding the second layer up to the top layer of the seam, it can realize two dimension tracing based on the memorial data, automatically determine the layer number and continually sway the welding head. The welding test shows that the machine has good tracing and welding behavior, and is suitable for spherical tank's all position multi layer welds.
