A nickel-chromium alloy similar to INCONEL alloy X-750 but with increased aluminum content for greater precipitation hardening. This alloy was designed for use as exhaust valves in internal-combustion engines. In that application, the alloy offers high strength at operating temperatures, high hot hardness for wear resistance, and corrosion resistance in hot exhaust gases containing lead oxide, sulfur, bromine and chlorine.

STANDARD PRODUCT FORMS

Round bar.

MAJOR SPECIFICATIONS

UNS N07751

LIMITING CHEMICAL COMPOSITION, %

Limiting
Nia.........70.0 min.
Cr...... 14.0 – 17.0
Fe...........5.0 – 9.0
^aPlus Co. bPlus Ta.
Ti.............2.0 – 2.6
Al.............0.9 – 1.5
Nb^b..........0.7 – 1.2
C...........0.10 max.
Mn.......... 1.0 max.
Si............ 0.5 max.
S...........0.01 max.
Cu........0.05 max.

PHYSICAL CONSTANTS AND THERMAL PROPERTIES

Density, Ib/in³..........................................................................0.299
g/cm³......................................................................... 8.28
Melting Point, °F......................................................2540 – 2600
°C......................................................1390 – 1430
Specific Heat, Btu/lb •°F.....................................................0.103
J/kg •°C........................................................... 431
Curie Temperature, °F........................................................... -193
°C.......................................................... -125
Permeability at 200 Oersted (15.9 kA/m).................. 1.0035
Coefficient of Expansion, 70 – 200°F, 10^-6 in/in •°F........ 7.0
21 – 93°C, μm/m •°C............. 12.6
Thermal Conductivity, Btu • in/ft²• h•°F...............................83
W/m•°C........................................... 12.0
Electrical Resistivity, ohm • circ mil/ft.............................. 731
μΩ•m................................................. 1.22

TYPICAL MECHANICAL PROPERTIES

INCONEL 783

INCONEL X-750