Ni-Span-C Alloy 902^* Specification
*Trade name of Special Metals Group

A precipitation hardenable Nickel-Iron-Chromium alloy having outstanding controllable thermoelastic coefficient characteristics and excellent oxidation resistance in high temperature atmospheres. The alloy can be processed to have a constant modulus of elasticity at temperatures ranging from -45 to +65^oC (-50 to +150^oF).

Good Mechanical Properties at Elevated Temperatures	No
Corrosion Resistant at Ambient Temperatures	No
Corrosion Resistant & Good Mechanical Properties at Elevated Temperatures	No
Oxidation Resistant	Yes
Precipitation Hardenable	Yes

Approximate Chemical Composition
Ni	41 - 43.5%
Cr	4.9 - 5.75%
Ti	2.2 - 2.75%
Fe	48%

Properties
DENSITY	8.05 g/cm3	0.291 lb/in3
MELTING POINT	1480oC	2700oF
COEFFICIENT OF EXPANSION	7.6 µm/m °C (20 - 100°C)	4.2 x 10-6 in/in °F (70 - 212°F)
MODULUS OF RIGIDITY	62 - 69 kN/mm2	8993 - 10008 ksi
MODULUS OF ELASTICITY	165 - 200 kN/mm2	23932 - 29008 ksi

CONDITION OF SUPPLY	HEAT TREATMENT (AFTER FORMING)
Spring Temper For good all round properties:	Age harden at 650°C (1200°F) for 2 hours and air cool.
For maximum stability:	1.  Stress equalise at 400°C (750°F) for 2 hours and air cool and 2.  Age harden at 650°C (1200°F) for 2 hours and air cool.
For min. hysterisis & low thermo elastic coefficient:	Stress equalise at 400°C (750°F) for 2 hours and air cool.

(Very high precision applications will require each batch to be pilot tested to determine the specific heat treatment necessary to produce the required thermo elastic coefficient).

CONDITION	APPROX TENSILE STRENGTH		APPROX SERVICE TEMPERATURE
Annealed	450 - 650 N/mm2	65 - 94 ksi	-45 to +65°C	-50 to +150°F
			(for constant modulus applications)
Spring Tempered	900 - 1100 N/mm2	131 - 159 ksi	-45 to +65°C	-50 to +150°F
			(for constant modulus applications)
Spring Temper + Aged	1300 - 1500 N/mm2	189 - 218 ksi	-45 to +65°C	-50 to +150°F
			(for constant modulus applications)