Composite pulsation spot welding process and system

Abstract

The invention discloses resistance spot welding process and a system, and relates to composite pulsation spot welding process and a system. By the aid of the composite pulsation spot welding process and the system, power-frequency spot welding current of traditional resistance spot welding process and condenser discharge pulses are combined. The condenser discharge pulses with high-current peak values and short discharge time are released in a weld nugget solidification stage after supply of the power-frequency welding current is finished and before supply of power-frequency temper current starts. The composite pulsation spot welding process is realized in the composite pulsation spot welding system, wherein the composite pulsation spot welding system comprises a power-frequency pulse portion, a condenser discharge portion and a synchronous system. By the aid of the composite pulsation spot welding process and the system, welding zone textures can be remarkably improved, crystal grains are refined, anisotropy is weakened, welding cracks are reduced, components are homogenized, and accordingly mechanical performances of resistance spot welding are enhanced.

Description

technical field [0001] The invention relates to a welding process in the field of welding technology, in particular to a compound pulse spot welding process and a welding system thereof. Background technique [0002] The traditional resistance spot welding process has been widely used in industrial production, especially in the field of automobile manufacturing, because of its simple metallurgical process and easy mechanization and automation. However, with the continuous improvement of the welding process and welding quality requirements, how to improve the welding zone structure and welding performance by designing the resistance spot welding current process parameters has become an important task in the research of resistance spot welding technology. [0003] F.Hayat in "The effects of the welding current on heat input, nugget geometry, and the mechanical and fractional properties of resistance spot welding on Mg / Al dissimilar materials" and the effect of welding current...

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Problems solved by technology

[0008] However, the tempering pulse of resistance spot welding is still limited to the power frequency cycle pulse, and there is no attempt to use the high current density peak value and short discharge time current pulse generated by the capacitor energy storage discharge as the tempering pulse

And from the hardware point of view, the current peak current of the AC welding machine needs to be greatly increased in the existing technology, which requires the entire AC pulse welding system to be upgraded, which is costly and difficult to guarantee stability.

However, the research on the discharge pulse treatment of melt capacitor energy storage is still limited to the field of casting, and their method of heating the metal to melting in the casting experiment is not the resistance heating in the resistance spot welding.

There is no research on the operability of capacitor energy storage discharge pulse tempering in resistance spot welding

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