This paper described the work of welding process design for the ＂ West-East＂ pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, clim...This paper described the work of welding process design for the ＂ West-East＂ pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, climate, culture and the flexibility of the welding methods, this work recommended the semi-automatic process at the east and middle sections and automatic process at the west section of the pipeline project. The manual process is recommended on the tie-in joints and repairs. The double joint pipe and the 3 joint pipe are recommended at the water net place and some in-ditch welding place to reduce the welding volume. Also the special redesigned bevels are recommended for the automatic process and the semiautomatic process. Through all destructive tests, the results shows the welds are meet the requirements of related standards, specifications and design documents.展开更多
In order to realize the automatic welding of pipes in a complex operation environment,an automatic welding system has been developed by use of all-position self-shielded flux cored wires due to their advantages,such a...In order to realize the automatic welding of pipes in a complex operation environment,an automatic welding system has been developed by use of all-position self-shielded flux cored wires due to their advantages,such as all-position weldability,good detachability,arc's stability,low incomplete fusion,no need for welding protective gas or protection against wind when the wind speed is<8 m/s.This system consists of a welding carrier,a guide rail,an auto-control system,a welding source,a wire feeder,and so on.Welding experiments with this system were performed on the X-80 pipeline steel to determine proper welding parameters.The welding technique comprises root welding,filling welding and cover welding and their welding parameters were obtained from experimental analysis.On this basis,the mechanical properties tests were carried out on welded joints in this case.Results show that this system can help improve the continuity and stability of the whole welding process and the welded joints'inherent quality,appearance shape,and mechanical performance can all meet the welding criteria for X-80 pipeline steel;with no need for windbreak fences,the overall welding cost will be sharply reduced.Meanwhile,more positive proposals were presented herein for the further research and development of this self-shielded flux core wires.展开更多
文摘This paper described the work of welding process design for the ＂ West-East＂ pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, climate, culture and the flexibility of the welding methods, this work recommended the semi-automatic process at the east and middle sections and automatic process at the west section of the pipeline project. The manual process is recommended on the tie-in joints and repairs. The double joint pipe and the 3 joint pipe are recommended at the water net place and some in-ditch welding place to reduce the welding volume. Also the special redesigned bevels are recommended for the automatic process and the semiautomatic process. Through all destructive tests, the results shows the welds are meet the requirements of related standards, specifications and design documents.
文摘In order to realize the automatic welding of pipes in a complex operation environment,an automatic welding system has been developed by use of all-position self-shielded flux cored wires due to their advantages,such as all-position weldability,good detachability,arc's stability,low incomplete fusion,no need for welding protective gas or protection against wind when the wind speed is<8 m/s.This system consists of a welding carrier,a guide rail,an auto-control system,a welding source,a wire feeder,and so on.Welding experiments with this system were performed on the X-80 pipeline steel to determine proper welding parameters.The welding technique comprises root welding,filling welding and cover welding and their welding parameters were obtained from experimental analysis.On this basis,the mechanical properties tests were carried out on welded joints in this case.Results show that this system can help improve the continuity and stability of the whole welding process and the welded joints'inherent quality,appearance shape,and mechanical performance can all meet the welding criteria for X-80 pipeline steel;with no need for windbreak fences,the overall welding cost will be sharply reduced.Meanwhile,more positive proposals were presented herein for the further research and development of this self-shielded flux core wires.
