316NF

The high levels of nickel and nitrogen in this alloy ensure the formation of a completely austenitic and non-magnetic weld deposit, with a maximum magnetic permeability of 1.01. The typical tensile strength exceeds 600 MPa thanks to the controlled level of nitrogen. A high manganese content prevents the formation of microcracks in the ferrite-free weld metal. Applications requiring non-magnetic properties include welding 316L fittings for minesweeper systems and collars for downhole instrumentation offshore. The fully austenitic microstructure guarantees excellent strength and toughness properties at critical low temperatures, making it ideal for joining LPG and LNG storage tanks in 304L and 316L. Toughness remains effective even at extreme temperatures, down to -269 °C, for superconductive applications. Unlike traditional 316L weld metals with ferrite, which can be attacked in concentrated nitric acid, this ferrite-free alloy offers excellent corrosion resistance and is suitable for direct overlays onto C-Mn steel. Preheating is not required, and the maximum interpass temperature is 150 °C.

Nil-ferrite, modified 316L alloy for non-magnetic, cryogenic and nitric acid applications.

Fully austenitic.

For type 316L and similar parent materials where ferrite-free and non-magnetic weld metal is required, also suitable for 304/304L and 316/316L for cryogenic service. May be suitable for welding 200 series stainless steels, and nitrogen strengthened stainless steels.

• ASTM: XM-19
• UNS: S20910
• PROPRIETARY: Nitronic® 50 (AK Steel), Fermonic ® 50 (Langley Alloys)