Inconel 718^* Specification
*Trade name of Special Metals Group of Companies

A Nickel-Chromium alloy being precipitation hardenable and having high creep-rupture strength at high temperatures to about 700^oC (1290^oF). It has higher strength than Inconel X-750 and better mechanical properties at lower temperatures than Nimonic 90 and Inconel X-750.

Good Mechanical Properties at Elevated Temperatures	Yes
Corrosion Resistant at Ambient Temperatures	Yes
Corrosion Resistant & Good Mechanical Properties at Elevated Temperatures	Yes
Oxidation Resistant	Yes
Precipitation Hardenable	Yes

Approximate Chemical Composition
Ni + Co	50 - 55%
Cr	17 - 21%
Fe	BAL
Nb + Ta	4.75 - 5.5%
Mo	2.8 - 3.3%
Ti	0.65 - 1.15%
Al	0.2 - 0.8%

Properties
DENSITY	8.19 g/cm3	0.296 lb/in3
MELTING POINT	1336°C	2437°F
COEFFICIENT OF EXPANSION	13.0 µm/m °C (20 - 100°C)	7.2 x 10-6 in/in °F (70 - 212°F)
MODULUS OF RIGIDITY	77.2 kN/mm2	11197 ksi
MODULUS OF ELASTICITY	204.9 kN/mm2	29719 ksi

CONDITION OF SUPPLY	HEAT TREATMENT (AFTER FORMING)
No 1 Spring Temper/Spring Temper	1. Solution Anneal at 980oC (1800oF) for 1 hour and air cool and 2. Age harden at 720oC (1330oF) for 8 hours and furnace cool to 620oC (1150oF) and hold at 620oC (1150oF) for a total age hardening time of 18 hours and air cool.
No.1 Spring Temper/Spring Temper (NACE MRO175)	1. 1010oC (1870oF) 2 hours and air cool. and 2. 790oC (1455oF) 6 hours and air cool.

CONDITION	APPROX TENSILE STRENGTH		APPROX SERVICE TEMPERATURE
Annealed	800 - 1000 N/mm2	116 - 145 ksi	-	-
No 1 Spring Temper	1000 - 1200 N/mm2	145 - 175 ksi	-	-
No 1 Spring Temper + Annealed + Aged	1250 - 1450 N/mm2	181 - 210 ksi	-200 to +550oC	-330 to +1020oF
Spring Temper	1300 - 1500 N/mm2	189 - 218 ksi	-	-
Spring Temper + Annealed + Aged	1250 - 1450 N/mm2	181 - 210 ksi	-200 to +550oC	-330 to +1020oF