Özet:

Hyper duplex stainless steels (HDSS), which are the most advanced products of the duplex stainless steel class, containing ferrite and austenite phases in high densities, still have a very niche and limited application area due to their cost and production process complexity. However, it is expected that the application areas will expand and its field of use will become widespread within the scope of developing technology and diversifying needs. The widespread use of this fairly new product group also depends on its machinability and weldability properties. Fusion welding methods can change the thermal history of the material and therefore the α/γ balance in duplex stainless steel. Therefore, friction stir welding method along with some arc welding with low heat input are the methods applied for joining hyper duplex stainless steels. In this study, hyper duplex stainless steels are introduced, their production methods, fields of use, and advantages are mentioned, and previous studies are evaluated by giving information about suitable welding methods and weldability.