The Resistance Spot Weldability of a Stainless Steel/Aluminium/Low Carbon Steel 3-Ply Clad Sheet

The present paper is aimed at investigating the resistance spot weldability of a 3-ply clad sheet comprised of stainless steel (SS), aluminium (Al) and low carbon steel (LCS). The weldability was assessed with the help of the weldable current range (WCR), the current range between the minimum current required to produce 4√t nugget diameter and a maximum current at which expulsion occurs. However, electrode-sheet sticking was found as the limiting factor instead of expulsion. It was observed that the introduction of aluminium to the SS/LCS clad increased the weld current range by shifting the expulsion to higher current, but resulted in melting of the electrode and subsequent electrode-sheet sticking. Key words: Weldability, Aluminium, Intermetallic compound layer, Electrode-sheet sticking, Liquid Cu penetration