The Effect Of Nugget Sizes On Mechanical Properties In Resistance Spot Welding Of SPA-C Atmospheric Corrosion Resistant Steel Sheets Used In Rail Vehicles*

Nuri Akkaş; Erdinç İlhan; Salim Aslanlar; Faruk Varol

doi:10.3139/120.110646

Article

The Effect Of Nugget Sizes On Mechanical Properties In Resistance Spot Welding Of SPA-C Atmospheric Corrosion Resistant Steel Sheets Used In Rail Vehicles*

Nuri Akkaş , Erdinç İlhan , Salim Aslanlar and Faruk Varol

Published/Copyright: October 11, 2014

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From the journal Materials Testing Volume 56 Issue 10

Abstract

This publication presents an experimental study on the resistance spot welding of SPA-C steel sheets used in side wall and roof application of rail vehicles. SPA-C atmospheric corrosion resistant steel sheets with a thickness of 2.3 mm were joined by using resistance spot welding as lap joint. A timer and current controlled resistance spot welding machine with 120 kVA capacity and a pneumatic application mechanism with a single lever were used to join the specimens. Welding periods were chosen as 5, 10, 15, 20, 25 and 30 cycles (1 cycle = 0.02 s) and also welding currents were increased from 6 kA up to 14 kA by rising in steps of 0.5 kA. The electrode force was kept constant at 6 kN. The welding joints obtained were exposed to tensile peel and tensile shear tests and their nugget sizes were calculated by results of optical microscopy measurements. The effect of nugget sizes on tensile peel strength and tensile shear strength was researched by using related diagrams and the optimum welding currents and times were advised.

Kurzfassung

Dieser Beitrag stellt eine experimentelle Studie über das Widerstandspunktschweißen von SPA-C-Stahlblechen vor, die in der Seitenwand und im Dach von Schienenfahrzeugen eingesetzt werden. SPA-C Stahlbleche mit einer Dicke von 2,3 mm wurden als Überlappungsverbindung widerstandspunktgeschweißt. Eine zeit- und stromgesteuerte Widerstandspunktschweißanlage mit einer Kapazität von 120 kVA und pneumatischer Einhandkrafterzeugung wurde verwendet, um die Proben zu verbinden. Es wurden Schweißzeiten von 5, 10, 15, 20, 25 und 30 Zyklen gewählt (1 Zyklus = 0,02 s). Der Schweißstrom wurde von 6 kA bis 14 kA in Schritten von 0,5 kA erhöht. Die Elektrodenkraft betrug konstant 6 kN. An den Schweißverbindungen wurden Schäl- und Scherzugversuche durchgeführt und die Größen der Schweißlinse wurden mittels optischer Mikroskopie ermittelt. Die Wirkung der Größe der Schweißlinse auf die Schäl- und Scherzugfestigkeit wurde unter Einsatz von entsprechenden Diagrammen bestimmt. Die optimalen Schweißströme und -zeiten wurden ermittelt.

**Correspondence Address Nuri Akkaş, Sakarya University, Faculty of Technical Education, 54187 Sakarya, Turkey, E-mail: akkas.nuri@gmail.com

Nuri Akkaş was born in 1975 in Sakarya, Turkey, where he completed his primary education. In 1999, he graduated from the Department of Naval Architecture and Marine Engineering at Yıldız Technical University in Istanbul, Turkey. He received a MSc degree in the Department of Mechanical Engineering at Sakarya University, in 2006. He has worked at the Başak Tractor Factory, Sakarya University as well as for the Turkish Standard Institute (TSE). Presently, he is continuing his PhD studies at Sakarya University, Faculty of Technical Education, and working for the Sakarya Metropolitan Municipality.

Dr. Erdinç İlhan completed his primary education in Sakarya, Turkey, and graduated from the Department of Metal Education, Marmara University, Turkey, in 1981. He received his MSc and PhD degrees from the Machine Department of that university. He worked as a production manager at the Alce-Östaş Company, Istanbul, Turkey, and headed the Department of Design and Construction Education at Sakarya University. Currently, he works in the Department of Metal Education at that university.

Prof. Dr. Salim Aslanlar was born in 1963 in Sakarya, Turkey. He graduated from Fachhochschule Niederrhein, Germany, Department of Mechanical Engineering in 1987. He acquired his PhD degree from the Department of Mechanical Engineering, Sakarya University, Turkey, in 1999. In 2002, he was appointed Director of the Vocational School of Geyve and in 2010 Director of Welding Technology Research, Testing and Implementation Center, Sakarya University. He teaches as a professor at that university, his areas of expertise being welding metallurgy, joining and brazing as well as cold metal transfer of dissimilar metals.

Dr. Faruk Varol, born 1978 in Balıkesir, Turkey, began his studies In 1998 at the Technical Training Faculty of Sakarya University, Turkey, from which he graduated in 2002. He has a Master of Education from the Department of Education, Institute of Metal Science, completing his education in 2006. In 2007, he began working on his PhD in the Institute of Metal Science and the Department of Education at Sakarya University, acquiring his PhD in 2014. He works in the Machine and Metal Technology Department of Karasu Vocational High School, Sakarya University.

Presented during the 3^rd International Conference on Welding Technologies and Exhibition (ICWET'14) in Manisa, Turkey

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Published Online: 2014-10-11

Published in Print: 2014-10-01

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https://doi.org/10.3139/120.110646