Device and method for controlling welding deformation of girth of thin-walled cylinder through thermal field regulation and control

Abstract

The invention provides a device and method for controlling girth welding deformation of a thin-walled cylinder through thermal field regulation and control, the device is composed of a supporting part, a resistance wire, an annular lock sleeve and other components, and the method comprises the steps that before welding, the device is placed on the inner wall of a cylinder body of the thin-walled cylinder to be welded, and after the resistance wire embedded in the device is powered on, the annular lock sleeve is locked to the inner wall of the cylinder body of the thin-walled cylinder to be welded; the supporting part and the annular lock sleeve absorb heat transmitted by the resistance wire and simultaneously generate outward and inward expansion, the expanded device enables the thin-wall cylinder structure to deform in the circumferential direction, and then pre-circumferential tensile stress of a certain size is formed in the cylinder structure before welding to serve as welding auxiliary stress. And the pre-circumferential tensile stress and dynamic stress in welding are coupled and superposed, so that the welding residual compressive stress of the welded thin-walled cylinder is lower than the critical instability stress of the thin-walled cylinder, and the instability deformation is eliminated, thereby controlling the girth welding deformation of the thin-walled cylinder.

Description

technical field [0001] The invention relates to the technical field of girth welding of thin-walled cylinders, in particular to a device and method for regulating and controlling the deformation of girth welding of thin-walled cylinders by a thermal field. Background technique [0002] In the era of pursuing lightweight, metal thin-walled structural parts are gradually chosen by many industries, such as stainless steel mixing containers for food processing, stainless steel pipes for tap water transportation, and thin-walled plates for building curtain walls. Larger wavy welding deformation is easy to occur during welding. This large welding deformation will bring many problems and hazards. If the thin-walled structural parts are used in the working condition of welding first and then matching, it will seriously affect the accuracy of the structure, making it difficult to achieve high precision such as flatness and roundness. If the installation and use cannot be completed a...

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Problems solved by technology

[0004] At present, the main methods of controlling the welding deformation of the structure during the welding process include the welding gas cooling method, the welding impact method, and the welding ultrasonic excitation method. These welding auxiliary methods can reduce the deformation of stainless steel thin-walled structures to a certain extent. Post-weld residual stress reduces post-weld welding deformation, but the extent of post-weld residual stress reduction and the degree of post-weld deformation cannot be quantitatively controlled with high accuracy, and the above welding deformation control method is easier to apply to thin-walled In the flat plate welding structure, the post-weld deformation control effect of the thin-walled cylindrical structure with high requirements for parameters such as roundness and concentricity is not good. Although the thin-walled cylinder can be placed on the inner wall of the ceramic support structure to assist welding, but this This kind of method can only play the role of fixed support in assembly, and cannot fundamentally reduce the residual stress of the structure after welding to make it lower than the critical instability stress. When the support is taken out, the previous deformation will also be restored.

Therefore, it is urgent to develop a new method to control the welding deformation of thin-walled cylinders in view of the difficulty in controlling the deformation of thin-walled cylinders.

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