Investigating the Effect of Friction Stir Welding on the Mechanical and Metallurgical Properties of Joining CK45 Steel to AISI 304L Stainless Steel

In the present study, considering the features and advantages of solid-state welding methods as compared with fusion welding methods such as arc welding, laser welding induction welding, and solid-state welding, they are used to connect CK45 steel to AISIS 304L steel to achieve the desired mechanical and metallurgical properties through experimental and practical tests, by trial and error, suitable parameters of distance, depth, and advance are obtained for welding, and finally a healthy and desirable weld is obtained. The purpose of the present study is to evaluate the weldability of CK45 steel to AISIS 304L steel by friction stir welding method. The distance, advance, and penetration depth parameters were experimentally determined as 950 rpm, 24 mm/min, and 0.35 mm, respectively, to obtain a healthy weld in terms of appearance. Then, through mechanical and metallurgical tests, the effect of the input parameters on the friction stir welding process was determined. The mechanical and metallurgical properties were also evaluated. The results show that the structure of the onion rings in the welding area is caused by the friction stir welding process, which is caused by the massive plastic deformation and the heat generated during the process. The scanning electron microscope image of the welded section of the steel sample shows the formation of a pearlite structure. Considering the severe plastic deformation and dynamic recrystallization in the friction stir welding process, the results obtained from the welding of dissimilar CK5 and AISI304 L show better mechanical properties and acceptable strength.