Nitronic 50 is a high-manganese (20Ni2Mo) stainless steel that exhibits excellent corrosion resistance and toughness. It is sometimes referred to as an austenitic-martensitic stainless steel. It has the properties of a martensitic stainless steel but with a higher strength than type 303 stainless steel. It has excellent mechanical properties at both room temperature and elevated temperatures up to 871 ℃. Moreover, the material is virtually nonmagnetic in the subjected conditions.
Nitronic 50 has excellent corrosion resistance to most of the common corrosive agents, including salt water and organic acids. It is resistant to intergranular corrosion and pitting corrosion. The material retains strength in severe oxidizing environments and is resistant to stress corrosion cracking. It exhibits excellent resistance to corrosion fatigue, which makes it suitable for a wide range of applications that require resistance to stresses and corrosive environments.
The microstructure of Nitronic 50 consists mainly of ferrite and austenite matrix with an average grain size of 4-6μm. The thin ferrite phase creates a softer microstructure that allows for superior ductility and toughness. However, at temperatures above 871℃, grain boundaries tend to recrystallize, leading to a detrimental effect on mechanical properties.
Nitronic 50 exhibits good weldability, with access to higher strength levels being achieved under proper conditions. It can be readily fusion welded using any commercially available argon-arc-welding process. It can be hot-worked at temperatures above 982°C to yield a uniform grain structure with a minimum of strain hardening.
In conclusion, Nitronic 50 is a high-manganese stainless steel with excellent corrosion resistance and extreme toughness. Its ability to withstand the hostile conditions of welding makes it suitable for a variety of applications in the chemical, medical and seawater industries. Its weldability and its mechanical properties allow it to be used in high-performance situations.
