Friction stir welding (FSW), recognized as an eco-friendly and safe welding technique, finds widespread application across industries including aerospace, and automotive sectors. As a key material in production, stainless steel (SS) has great application potential in FSW. In this article, solid-state joining of dissimilar materials 2507 super duplex stainless steel (SDSS) and 317 L austenitic stainless steel (ASS), using FSW was investigated. By adjusting the position of 2507 SDSS and 317 L ASS, this paper examined the mechanical and surface properties of the joints at rotation speed of 400 rpm and welding speed of 20 mm/min. The results revealed that alteration of the material position seemed to have negligible influence on the joint's appearance, tensile behavior, and failure location. However, a clear grain refinement post-FSW in the joints was recorded, leading to a substantial increase in the hardness of the center stir zone (CSZ), alongside noticeably enhanced wear resistance. This grain refinement also contributed to an improvement in the corrosion resistance of the joints.