A resistance spot welding method under the action of a controllable rotating magnetic field

Abstract

The invention relates to a resistance spot welding method under the action of a controllable rotating magnetic field, which belongs to the field of welding technology. The invention solves the defects of low resistance spot welding spot strength and coarse structure, and the magnetic field direction of the magnetron resistance spot welding is not parallel to the workpiece, and the stirring effect of the Lorentz force generated under the action of the magnetic field depends on the conduction current. The specific steps are: clamp and fix the welding workpiece; adjust the welding parameters of the resistance welding machine; when the welding system is turned on, turn on the magnetic field generator, set the frequency, intensity, and phase of the exciting three-phase alternating current; check the air pressure system, determine the welding position; start The magnetic field generating device sends a signal to the welding system; the welding system monitors the signal of the magnetic field monitoring system; starts the welding system and performs welding; when the welding process ends, the electrode head is lifted and the magnetic field generating device is turned off. The invention can be used for resistance spot welding of metal plates in the industrial field, has obvious effect of grain refinement in nugget area of ​​joints after welding, improves tensile strength and improves welding quality.

Description

technical field [0001] The invention relates to a resistance spot welding method, in particular to a resistance spot welding method under the action of a controllable rotating magnetic field, and belongs to the field of welding technology. Background technique [0002] Resistance spot welding is a traditional welding method widely used in vehicle structure welding, but in the actual resistance welding process, there are the following problems: [0003] 1) The welding area is small, the cooling speed of the weld nugget area is fast, and the grains are coarse. [0004] 2) There is a large internal stress, resulting in relatively poor mechanical properties of the joint. [0005] In order to solve the above problems, inspired by electromagnetic metallurgy, it is possible to stir the nugget area of ​​the resistance spot welding joint by extending the electromagnetic stirring principle in the metallurgical industry to the process of resistance spot welding. At the same time, ins...

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Problems solved by technology

[0004] 2) There is a large internal stress, resulting in relatively poor mechanical properties of the joint

However, the device used to generate the magnetic field in the paper has certain limitations:

[0011] 2) The movement mode of the magnetic field is single, and it is radially tiled on the surface of the workpiece. The magnetic field cannot be rotated, and the size, direction, and frequency of the rotation cannot be adjusted.

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