Tianjin University

Zhaowei Xue

Lei Zhao

Lianyong Xu

Yongdian Han

Kangda Hao

A high-heat-input combined welding method for thick-walled high-strength steel includes following steps. First, a steel plate to be welded is machined into an asymmetric double-sided V-groove, with a depth of a front groove ranging from 30 mm to 40 mm. Then, electrogas welding is used to fill and weld the front groove, with a single-pass heat input controlled below 300 KJ/cm. Finally, a back groove is filled and welded, ensuring that the single-pass heat input for the back groove does not exceed that of the front groove. By adopting an asymmetric double-sided V-groove, the steel plate to be welded is divided into front and back sections. The depth of the groove is restricted to limit the heat input during filling welding.

High-heat-input combined welding method for thick-walled high-strength steel

A high-strength, high-toughness, and corrosion-resistant welding method for TKY nodes in a deepwater jacket includes the following steps: preheating T/K/Y nodes at a predetermined temperature according to a wall thickness of a base material; setting different welding parameters for different welding processes; and performing rooting weld on the preheated T/K/Y nodes through an electrode arc welding process, then performing filling weld through a gas metal arc welding process, and finally performing capping weld through the gas metal arc welding process. A corresponding electrode is selected for the rooting weld, a welding wire is selected for the capping weld according to low-strength matching, a welding wire is selected for the filling weld according to an equal-strength matching principle, and diffusible hydrogen contents of any electrode and any of the welding wires are all less than or equal to a predetermined diffusible hydrogen content.

High-strength, high-toughness, and corrosion-resistant welding method for TKY nodes in deepwater jacket

A method of automatically welding a welded seam of a saddle line for a saddle-type T joint belonging to the technical field of welding is provided, including: establishing a groove cross-sectional model, solving a variation law of a groove cross-sectional area, and planning a welding bead and a welding process parameter according to the groove cross-sectional area; establishing a welding torch pose mathematical model and obtaining a pose homogeneous transformation matrix T of a welding torch; establishing a three-dimensional model of a main pipe and a branch pipe, building a welding system through offline software, importing welding spot pose information, and generating welding torch pose offline command through the offline software; and performing automatic welding of the welded seam of the saddle line for the saddle-type T joint according to the planned welding bead and the welding process parameter and the generated welding torch pose offline command.

Method of automatically welding welded seam of saddle line for saddle-type T joint

The invention belongs to the field of welding technology and discloses a CMT automatic overlaying method for opening in side wall of bimetallic composite pipes. The method includes: establishing a mathematical model of the opening in a side wall to be welded; Based on the mathematical model, determining the trajectory of the saddle line during overlaying; dividing the trajectory of the saddle line into several welding runs, all of which adopt the downslope welding process; establishing a three-dimensional model of the opening in the side wall to be welded and a CMT overlaying system simulation model; Based on the simulation model, planning the overlaying path of the CMT overlaying, and generating an overlaying offline instruction; Based on the offline instruction, performing CMT overlaying on the opening in the side wall to be welded according to the overlaying sequence, so as to obtain a weld overlay.

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Tianjin, China

Zhaowei Xue