The local induction heating process and the whole induction heating process were adopted to develop the X80 Ф1219 mm × 22 mm induction bends in this paper. After the tempering of the bends, the effect of inducti...The local induction heating process and the whole induction heating process were adopted to develop the X80 Ф1219 mm × 22 mm induction bends in this paper. After the tempering of the bends, the effect of induction heating on the properties of X80 longitudinal submerged-arc welding line pipe was studied. The results show that for the X80 bend manufactured via the local induction heating, both the tensile strength and yield ratio of unquenehed straight tangents are higher than those of the quenched bend area. The toughness of straight tangents is lower than that of the bend area. The strength and toughness of straight tangents do not match pegrectly that of the bend area. The induction heating can improve effectively the toughness of weld pipe, reduce the tensile strength and yield ratio to some extent. The whole induction heating makes the match of properties between the straight tangents and the bend area reasonable, thus it is an optimum process for the manufacturing of X80 induction bend.展开更多
During the process of laying long-distance oil and gas transmission pipelines, the hot-induction-bend method is extensively used when the direction has to be changed. By considering the pipeline＇ s ongoing processing...During the process of laying long-distance oil and gas transmission pipelines, the hot-induction-bend method is extensively used when the direction has to be changed. By considering the pipeline＇ s ongoing processing and loading states during service, the pipeline that is generally used exhibits thicker walls than those that are observed in the line pipe. As such, during pipeline construction, hot-induction-bend and line pipes with different wall thickness are girth-welded. The chemical composition of hot-induction-bend and line pipes differs, with the carbon content being particularly higher in the hot-induction-bend pipe;it also depicts a higher carbon equivalent, which makes it possible to modify the girth of the pipe. In this study, using Baosteel＇ s standard X70M UOE hot- induction-bend and line pipes, solid-wire automatic gas-metal-arc girth welding was performed and the performance of the girth-welded joint was evaluated. Furthermore,the weldability of the pipeline girth and the microstructure of the girth-welded joint were analyzed. The results reveal that Baosteel＇ s standard UOE hot-induction-bend and line pipes exhibit good girth weldability, and their technical quality can be guaranteed in case of consumer field- construction applications.展开更多
Mechanical properties of weld metal are the key factors affecting the quality of heavy-wall X80 hot induction bends. The effects of bending parameters on the mechanical properties of weld metal for hot bends were inve...Mechanical properties of weld metal are the key factors affecting the quality of heavy-wall X80 hot induction bends. The effects of bending parameters on the mechanical properties of weld metal for hot bends were investigated by simulation conducted on a Gleeble 3500 thermal simulator. Continuous cooling transformation （CCT） dia- grams of the weld metal were also constructed. The influences of hot bending parameters （such as reheating temperature, cooling rate, and tempering temperature） on the microstructure and mechanical properties of weld metal were also analyzed. Results show that the strength of all weld metal specimens is higher than the value indicated in the technical specification and increases with the increase of reheating temperature, cooling rate, and tempering tempera ture. The impact toughness is apparently related to the variation of reheating temperature, cooling rate, and tempering temperature.展开更多
文摘The local induction heating process and the whole induction heating process were adopted to develop the X80 Ф1219 mm × 22 mm induction bends in this paper. After the tempering of the bends, the effect of induction heating on the properties of X80 longitudinal submerged-arc welding line pipe was studied. The results show that for the X80 bend manufactured via the local induction heating, both the tensile strength and yield ratio of unquenehed straight tangents are higher than those of the quenched bend area. The toughness of straight tangents is lower than that of the bend area. The strength and toughness of straight tangents do not match pegrectly that of the bend area. The induction heating can improve effectively the toughness of weld pipe, reduce the tensile strength and yield ratio to some extent. The whole induction heating makes the match of properties between the straight tangents and the bend area reasonable, thus it is an optimum process for the manufacturing of X80 induction bend.
文摘During the process of laying long-distance oil and gas transmission pipelines, the hot-induction-bend method is extensively used when the direction has to be changed. By considering the pipeline＇ s ongoing processing and loading states during service, the pipeline that is generally used exhibits thicker walls than those that are observed in the line pipe. As such, during pipeline construction, hot-induction-bend and line pipes with different wall thickness are girth-welded. The chemical composition of hot-induction-bend and line pipes differs, with the carbon content being particularly higher in the hot-induction-bend pipe;it also depicts a higher carbon equivalent, which makes it possible to modify the girth of the pipe. In this study, using Baosteel＇ s standard X70M UOE hot- induction-bend and line pipes, solid-wire automatic gas-metal-arc girth welding was performed and the performance of the girth-welded joint was evaluated. Furthermore,the weldability of the pipeline girth and the microstructure of the girth-welded joint were analyzed. The results reveal that Baosteel＇ s standard UOE hot-induction-bend and line pipes exhibit good girth weldability, and their technical quality can be guaranteed in case of consumer field- construction applications.
基金Sponsored by National Natural Science Foundation of China(51171162)R & D Project of CITIC-CBMM(2011-D056-3)
文摘Mechanical properties of weld metal are the key factors affecting the quality of heavy-wall X80 hot induction bends. The effects of bending parameters on the mechanical properties of weld metal for hot bends were investigated by simulation conducted on a Gleeble 3500 thermal simulator. Continuous cooling transformation （CCT） dia- grams of the weld metal were also constructed. The influences of hot bending parameters （such as reheating temperature, cooling rate, and tempering temperature） on the microstructure and mechanical properties of weld metal were also analyzed. Results show that the strength of all weld metal specimens is higher than the value indicated in the technical specification and increases with the increase of reheating temperature, cooling rate, and tempering tempera ture. The impact toughness is apparently related to the variation of reheating temperature, cooling rate, and tempering temperature.
