Investigating the Effect of Film in SSRSW of Hastelloy X Superalloy

 At this paper, a new equation has been presented to calculate the electrical resistance caused by constriction and presence of surface films on the sheets in small scale resistance spot welding. Then, the simulations have been conducted using the new model and its validity has been evaluated. Experimental verification was carried out on sheets made of Hastelloy X and it was found that the experimental nugget diameters have a good agreement with the results of the simulation. The maximum nugget diameter was created in the case of thin film. Also, existence of film layer improves tensile strength. At the presence of thick film the height of the weld is maximum that can be due to expulsion.