NIMONIC 80A Alloy

NIMONIC 80A Alloy

NIMONIC alloy 80A (UNS N07080/W. Nr. 2.4952 & 2.4631) is a wrought, age-hardenable nickel-chromium alloy, strengthened by additions of titanium, aluminum and carbon developed for service at temperatures up to 815°C (1500°F). It is produced by high-frequency melting and casting in air for forms to be extruded. Electroslag refined material is used for forms to be forged. Vacuum refined versions are also available. NIMONIC alloy 80A is currently used for gas turbine components (blades, rings and discs), bolts, nuclear boiler tube supports, die-casting inserts and cores, and for automobile exhaust valves. The alloy’s limiting chemical composition is given in Table 1 (as in British Standard HR1, 201, 401 and 601).

NIMONIC alloy 80A Chemical Composition, %:

Carbon………………………………………………………………0.10 max.

Chromium…………………………………………………………..18.0-21.0

Silicon ………………………………………………………………….1.0 max

Copper………………………………………………………………..0.2 max.

Iron……………………………………………………………………..3.0 max.

Manganese ………………………………………………………….1.0 max.

Titanium…………………………………………………………………1.8-2.7

Aluminum ………………………………………………………………1.0-1.8

Cobalt …………………………………………………………………2.0 max.

Boron ………………………………………………………………0.008 max.

Zirconium…………………………………………………………..0.15 max.

Lead………………………………………………………………0.0025 max.

Sulfur ………………………………………………………………0.015 max.

Nickel………………………………………………………………….Balance

Heat Treatment

The heat treatments recommended for NIMONIC alloy 80A are as follows:

For extruded bar 8h/1080°C (1976°F)/air cool + 16h/700°C (1292°F)/air cool.

For extruded bar, subsequently cold stretched 8h/1080°C (1976°F)/air cool + 24h/850°C (1562°F)/air cool + 16h/700°C (1292°F)/air cool.

For cold rolled sheet 2-3 minutes/1150°C (2102°F)/ fluidized bed quench + 20 minutes/1040°C (1904°F)/air cool+4h/750°C(1382°F)/air cool.

For welded sheet 2 minutes/1150°C (2102°F)/air cool + weld + 1h/925°C (1697°F)/air cool + 4h/750°C (1382°F)/air cool.

For interstage annealing of sheet 20 minutes/1040°C (1904°F)/air cool.

Available Products and Specifications

NIMONIC alloy 80A is designated as UNS N07080 and Werkstoff Numbers 2.4952 and 2.4631. The alloy is available as sheet, round bar, flat bar, forging stock, hexagon, wire, plate and extruded section.

Specifications and designations include:

Rod, Bar, Wire and Forging Stock – BS 3076 & HR 1; ASTM B 637; AECMA PrEn 2188, 2189, 2190, 2396, 2397; AIR 9165-37

Plate, Sheet and Strip – BS HR 201, AECMA PrEn 2191

Pipe and Tube – BS HR 401

Other – BS HR 601, DIN 17742, AFNOR NC 20TA