International Journal of Scientific Research and Engineering Development-– Volume2 Issue 2, Mar –Apr 2019 Available at www.ijsred.com ISSN : 2581-7175 ©IJSRED: All Rights are Reserved Page 403 A Review on Resistance Spot Welding of Steel Material Shaymaa Abdul Khader Al-Jumaili *, Raed A.M Al-Mamoori ** *(Al-Mussaib Technical College, Al-Furat Al-Awsat Technical University, 51009 Babylon) ** (Al-Mussaib Technical College, Al-Furat Al-Awsat Technical University, 51009 Babylon) ----------------------------------------************************---------------------------------- Abstract: The resistance spot welding is an efficient welding method. However, the resulted joints are affected by some parameters such as welding current, welding time, and electrode force. The effect of welding parameters on the mechanical properties and failure mode is reviewed in this study. The relationship between the joint strength and welding parameters is presented. The nugget diameterand metallurgy, loading and micro hardness were the target points to be evaluated in this study. The effect of annealing heat treatment on the weldment properties was investigated as well. Few of investigations studied the defect formation in spot weld. The most critical defects such as cracks and cavities are presented as well as the residual. Besides, the effect of welding environments on the joint properties is reviewed in this study. Dissimilar joining of aluminum and steel by using resistance spot welding represents a critical aim in vehicle manufacturing, it is a key challenge for multi-materials lightweight design strategy, and therefore, many investigations studied the dissimilar joining via RSW. Keywords —Resistance spot welding, Joint strength, Dissimilar joining, Aluminum and Steel. ----------------------------------------************************---------------------------------- I. INTRODUCTION Resistance spot welding (RSW) is the process of joining two or three metal sheets via fusion at discrete spots at the sheets interface. It is widely used in many industrial sections such as aviation and transport applications (Fig 1). Fusion occurs according to heat generated from resistance to flow of the current through metal sheets [1, 2]. Temperature rises at the faying surfaces until reaching the plastic point of the metal, at high temperature the metal begins to fuse and a nugget will form. Then the current is switched off and weld nugget is allowed to cool down slowly until solidifying under pressure, (as shown in Fig 2). This process is completed within a short period; it may not exceeding parts of the second [3]. Professor Elihu Thomson invented the RSW process in 1877, and since then it has been extensively used in the manufacturing industries for joining metal sheets [4]. Many papers deal with the spot welding process and its variables in different subjects and fields. RESEARCH ARTICLE OPEN ACCESS Fig. 1 Resistance spot welding processes [1].