Inconel X750 Specification
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Inconel X750 Specification

X750 is a Nickel-Chromium alloy made precipitation hardenable by additions of Al and Ti, having creep-rupture strength at high temperatures to about 700oC (1290oF). It is widely used for high temperature conditions but is not as strong as Nimonic 90, and the Inconel X750 Nickel alloy springs are used in all Foyo's Trunnion mounted Ball valves

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

Applications include:

  • Nuclear reactors
  • Gas turbines
  • Rocket engines
  • Pressure vessels
  • Aircraft structures
Approximate Chemical Composition
Ni + Co 70% Minimum
Cr 14 - 17%
Fe 5 - 9%
Ti 2.25 - 2.75%
Al 0.4 - 1.0%
Nb + Ta 0.7 - 1.2%
Properties
DENSITY   8.28 g/cm3 0.299 lb/in3
MELTING POINT   1430 oC 2600 oF
COEFFICIENT OF EXPANSION   12.6 µm/m °C 
(20 - 100°C)
7.0 x 10-6 in/in °F
(70 - 212°F)
MODULUS OF RIGIDITY   75.8 kN/mm2 10994 ksi
MODULUS OF ELASTICITY  
 ** 
 *** 
218.0 kN/mm2
212.4 kN/mm2
213.7 kN/mm2
31619 ksi
30806 ksi
30995 ksi

*Spring Temper + Aged    **Spring Temper + 3 Part Heat Treated

*** No.1 Spring Temper + Aged

CONDITION OF SUPPLY HEAT TREATMENT (AFTER FORMING)
Spring Temper Age harden at 650oC (1200oF) for 4 hours and air cool.
Spring Temper 3 Part Heat Treatment:
1. Solution Anneal at 1150ºC (2100ºF) for 2 hours and air cool 
2. and Stabilise at 843ºC (1550ºF) for 24 hours and air cool 
3. and Age harden at 704ºC (1300ºF) for 20 hours and air cool
No 1 Spring Temper Age harden at 730ºC (1350ºF) for 16 hours and air cool

 for diameters below 1.00mm contact AWI quality department.

CONDITION APPROX TENSILE STRENGTH APPROX SERVICE TEMPERATURE
Annealed 800 - 1000 N/mm2 116 - 145 ksi    
Spring Temper 1100 - 1500 N/mm2 159 - 217 ksi    
Spring Temper + Aged 1350 - 1750 N/mm2 196 - 254 ksi -200 to +370 ºC -330 up to +700 ºF
Spring Temper + 3 Part heat treated 1100 - 1250 N/mm2 159 - 181 ksi -200 to +550 ºC -330 up to +1020 ºF
No 1 Spring Temper 900 - 1150 N/mm2 130 - 167 ksi    
No 1 Spring Temper + Aged 1300 - 1450 N/mm2 188 - 210 ksi -200 to +550 ºC -330 up to +1020 ºF