Fermonic® 50 – Annealed is a nitrogen-strengthened austenitic stainless steel supplied in the annealed condition (it is also known as Nitronic® 50 – a trademark owned by AK Steel Corporation). It provides almost double the yield strength of common austenitic stainless steel grades such as Alloy 304 and Alloy 316L, offering the potential to reduce section size and therefore weight and cost. Higher strength can be achieved through cold working. Importantly, it remains fully austenitic – and therefore, fully non-magnetic – even after severe cold-working.
This product maintains excellent ductility and toughness at both elevated and cryogenic temperatures, combined with improved abrasion and erosion resistance relative to other austenitic stainless steel grades, making it a useful and cost-effective alloy in a wide range of demanding applications. It can generally be formed and welded in the same way as other 3xx alloys, although machining may require slower speeds / more power due to its high work hardening rate. It achieves corrosion resistance equivalent or better than Alloy 317L in a wide range of environments, and is listed in NACE MR 01 75 for sour service given its ability to resist sulphide stress cracking.
|0.2% Proof Stress||380 N/mm2||55 ksi|
|Tensile Strength||690 N/mm2||100 ksi|
|Elongation, 5.65√S0 and 4D||35%|
|Reduction of Area||55%|
|Hardness (Brinell)||293 max.|
|Impact Strength (Room Temp)||54J av|
|Impact Strength (-60oC)||27J av (20J min)|
|Magnetic Permeability (20°C)||<1.05|
|Young’s Modulus (kN/mm2)||197|
|Specific Electrical Resistance, 20°C (µΩ-m)||0.82|
|Mean coefficient of thermal expansion, 20-100°C (m/m/°C)||17.9 x 10-6|
|Specific Heat, 20°C (J/kg.K)||475|
|Thermal conductivity, 20°C (W/m.K)||13.3|