316NF

The elevated nickel and nitrogen levels yield a fully austenitic, non-magnetic weld deposit with a maximum magnetic permeability of 1.01 H/m. Controlled nitrogen levels contribute to achieving a typical tensile strength above 600MPa. The high manganese content ensures freedom from microfissuring in the ferrite-free weld metal. Applications that benefit from non-magnetic properties include welding 316L fittings for minesweepers and offshore downhole instrumentation collars. The fully austenitic microstructure provides excellent strength and toughness at cryogenic temperatures, suitable for joining 304L and 316L LPG and LNG storage vessels. Useful toughness is maintained down to liquid helium temperatures (-269°C) for superconducting applications. In contrast to conventional 316L weld metal containing ferrite, which is susceptible to preferential attack in concentrated nitric acid, the nil-ferrite alloy exhibits excellent resistance and is suitable for direct deposition onto CMn steel to provide corrosion-resistant overlays. No preheat is 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).