Abstract: bGood weldability between LF6 alloy and HR-2 steel is very important for the production of the special pressure vessel made up with LF6 alloy sphere and HR-2 steel pipe.In order to improve the welding quality between this two kinds of materials,we explore experimentally the characteristics and mechanical properties of the friction welded joints of LF6 anti-rust aluminum and HR-2 anti-hydrogen stainless steel.Magnesium in LF6 aluminum alloy is easy to form the brittleness intermetallic compounds on the friction welding interface during the friction welding of LF6 and HR-2 steel,which not only leads to bad weldability,but also results in lower strength of the welded joint.In order to solve this problem,a "three-body" method has been used in our experiments.By means of adding pure aluminum film to the friction surface and cleaning oxide film on the friction welding interface of LF6 and HR-2 before welding,the tensile fracture strength of the welded joints can reach or exceed 270 MPa.Adopting the pure aluminum film as intermediate layer during the friction welding of LF6 alloy and HR-2 steel,we can prevent the formation of intermetallic compound on the friction welding interface.