Weld bonding process analysis for tensile shear strength and peel strength of weld bonded joints of dissimilar steel sheets

Abstract

Evaluating the strength performance of resistance spot welded joints in dissimilar material is critical for their continued integration into the automobile and aerospace industries. The effect of joint strength is an important consideration in the design of welded structures. The aim of this paper is to evaluate the effect of the welding process parameters (welding current, weld time, and electrode pressure) on the mechanical performance of dissimilar weld bonds between austenitic stainless steel 304L and low carbon steel sheets. Mechanical properties of weld bonds are described in terms of bond strength, failure mode, and hardness of the joint. Weld bonding experiments were planned on the basis of full factorial design matrix. Weld bonded joint strength tests showed that the maximum tensile shear strength and peel strength were achieved at 6.4 kA, eight-cycle weld time with 3 kg/cm2 electrode pressure. The hardness value across the weld bonded fusion zone was not affected much with respect to varying the welding current. Pullout failure and tearing failure modes were observed during the tensile shear strength test of weld bonded joints. Application of adhesive layer at faying surfaces resulted not only in strengthening but also distributing the stress in weld bonded joints.