AMS 5561 is a sub-type specification of Stainless Steel 21-6-9, which is a nitrogen-strengthened austenitic alloy with high manganese content. This specification is characterized by excellent resistance to oxidation at higher temperatures, high strength, and low magnetic permeability.
Tech Steel & Materials offers AMS 5561 in drawn tubing. As such, the specification is mostly used for manufacturing high-pressure hydraulic tubing, tailpipes, and exhaust systems in the aircraft industry, but also parts in chemical and pollution control equipment.
AMS 5561 can be welded using shielded fusion and resistance welding, although oxyacetylene welding should be avoided to minimize carbon buildup in the weld. When welded with suitable filler metal, the welds possess excellent intergranular corrosion resistance.
Moreover, this specification can be cold-worked using all traditional methods, although it requires higher force due to the high work-hardening rate of the alloy.
Meanwhile, the best temperature for hot working is considered 2100 °F to 2200 °F (1150 °C to 1200 °C), with a minimum temperature of about 1200 °F (650 °C).
AMS 5561 can be strengthened using hot- and -cold-working processes. The recommended temperatures range from 1200 °F to 1500 °F (650 °C to 815 °C), followed by stress relief at 900 °F to 1400 °F (480 °C to 760 °C).