Study on Flow Phenomenon in Spot Welding Nugget of Dissimilar Materials

Abstract:

Flow phenomenon in spot welding nugget of dissimilar materials was studied. Metallographs in the course of welding nugget formation were observed and analyzed, through which it was indicated that: in the early stage of welding nugget formation, spot welding of dissimilar materials made liquid metals in the nugget produce a violent stirring action because the electrodynamic force overcame the medium resistance, causing unevenness of elements and compositions in the welding nugget; and then the unevenness was represented by vortex flow by means of different resistances to corrosion. It was proposed that the formation law of welding nugget could be recognized according to the formation law of vortex flow, and the vortex flow often moved from later-molten metal to former-molten metal. The property of welded joint with vortex flow was poorer than that without vortex flow.

• Periodical: Advanced Materials Research (Volumes 1004-1005)
• Pages: 1093-1098
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1004-1005.1093
• Online since: August 2014
• Authors: Xu Gao, Ke Qiang Yu, Xiao Hong Chen
• Keywords: Dissimilar Materials, Electrodynamic Force, Medium Resistance, Vortex Flow

References

[1] Gao, X, Wang Gengzhu. (2004). Research on Fusion Course of Different Material in Spot Welding. Hot Working Technology, (8): 42-44.

[2] Zhao, X., Zhu, M., Tu, G. & Xuan, Z. (1995). Approach to Formation of Thin Piece Welding Nugget Vortex Flow. Transactions of the China Welding Institution, (1): 36-39.

[3] Александр Яковлевич Орлов. (Ed. ). (1980). Resistance Welding Technology and Equipment. Beijing: National Defense Industry Press.

[4] Bi, H. (Ed. ). (1981). Electric Resistance Welding. Beijing: China Machine Press.