Incoloy 903(UNS  N19903)

1.Incoloy 903 INTRODUCTION

A nickel-iron-cobalt alloy with additions  of niobium, titanium and aluminum for  precipitation hardening. The alloy combines high  strength with a low and constant coefficient of  thermal expansion at temperatures to about  800°F (430°C). It also has a constant modulus  of elasticity and is highly resistant to thermal  fatigue and thermal shock. Used in gas turbines  for rings and casings.

2.Incoloy 903 STANDARD  PRODUCT FORMS

Sheet, plate, rod, bar and forging stock.

3.Incoloy 903 MAJOR  SPECIFICATIONS

UNS N19903

4.Incoloy 903 LIMITING CHEMICAL  COMPOSITION, %

Ni......36.0 – 40.0 

Fe......Remainder  

Co..... 13.0 – 17.0 

Al ......0.30 – 1.15 

Ti ......1.00 – 1.85  

Nb.....2.40 – 3.50

5.Incoloy 903 PHYSICAL CONSTANTS  AND THERMAL  PROPERTIES

Density, Ib/in3 ........................................................................0.298 

g/cm3 ......................................................................... 8.25 

Melting Range, °F ...................................................2405 – 2539

°C ...................................................1318 – 1393 

 Specific Heat, Btu/lb•°F ....................................................0.105

J/kg•°C........................................................... 442 

Curie Temperature, °F ...............................................780 – 880 

°C ...............................................415 – 470 

Coefficient of Expansion, 77 – 800°F, 10-6 in/in •°F........4.0 

25 – 427°C, μm/m •°C ............ 7.2 

Thermal Conductivity, Btu • in/ft2•h•°F........................... 116

W/m •°C.......................................... 16.7 

Electrical Resistivity, ohm • circ mil/ft............................... 379 

μΩ•m..............................................0.650

6.Incoloy 903 TYPICAL MECHANICAL  PROPERTIES

(Precipitation Hardened) 

Tensile Strength, ksi............................................................... 190 

MPa..........................................................1310 

Yield Strength (0.2% Offset), ksi........................................ 160 

MPa...................................1100 

Elongation, % ..............................................................................14