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The base metal used in this study was high strength low alloy (HSLA) AH-36 steel. The welding process used the E6013 as a rutile electrode. Four rutile electrodes were produced by adding Mg metal powder, ranging from 0 to 5 wt.%, to the initial electrode layer in such a way as to obtain Mn and Si deposits according to ANSI/AWS standard A5.1-91. The shielded metal arc welding (SMAW) method was used with heat inputs of 1.5 kJ/mm and 2.5 kJ/mm. The tensile property, Charpy-V impact, and microhardness tests were performed to measure the mechanical properties of the weld metal. The observation of the metallographic structure was performed using an optical microscope. The results showed that with the increase of Mg layer content, the metal-oxygen level decreased, and the content of Mn and Si increased. The toughness and tensile strength of AH-36 steel improved, and the optimal Mg content is determined.

All metals have unique advantages and disadvantages in terms of their mechanical properties. Advantages such as flexibility are needed for construction and for the manufacture of sophisticated products. Some industries have improved the mechanical properties of metals by welding dissimilar ones together, such as aluminum alloy (AA) to stainless steel (SS) to reduce vehicle weights in order to improve fuel consumption. However, little research has been conducted on using micro resistance spot welding (mRSW) to join SS and Al by inserting a zinc (Zn) sheet between them as an interlayer. In this study, the mechanical properties of the weldment are tested using a shear test and Vickers micro hardness test. The results are compared using welding times of 6, 8 and 10 cycle times (CTs) and welding currents of 5 and 8 kA during the mRSW process. It is found that the SS, Zn and AA sheets could be joined with mRSW using an 8 kAA welding current and a 6 CT welding time. The micro hardness in the AA-Zn dissimilar joint increased relative to SS-Zn. Using a Zn sheet also improved displacement in the tensile shear test; however, it also increased the hardness of the diffusion zone.