What is the machinability of INCONEL X750?
Inconel X750 (also known as UNS N07750) is a nickel-chromium alloy mixed with aluminum and titanium to make it precipitation hardenable. It is corrosion and oxidation resistant and has good mechanical properties including high tensile strength and creep rupture strength at high temperatures up to 700°C (1290°F). In addition, Inco X750 has good strength and toughness in both solution and precipitation heat treated conditions. As a result, IN X750 is frequently used in parts and structures that operate under high temperature conditions. Typical aerospace applications include rotor blades, wheels and bolts for gas turbines, thrust chambers for jet and rocket engines, hot air duct systems, and thrust reversers for fuselages. It is also used in large pressure vessels, forming tools, extrusion dies, nuclear power plant applications, and heat treating units.
At Gnee Steel, we have 18+ years of experience supplying Inconel x750 forgings and many other product forms to your custom sizes and shapes. Our forging processes include open die forging, ring rolling, and more. See below for a list of common forged shapes and product forms we offer.
Inconel X750 Additional Information:
Physical Properties
Hardness: HRC 32 – 42 in solution and precipitation heat treated conditions (depending on heat treatment).
Density: 0.299 lb/in3.
Modulus of Elasticity: 31 MSI in STA condition.
Coefficient of Expansion: 7.8 x10-6 in/in/degF, RT-800F. 8.4 x10-6 in/in/degF, RT-1200F.
Machining
Inco X750 has a machinability rating of 16. Like other nickel-based high temperature alloys, Inconel X-750 is not as machinable as most steels, including stainless steels. However, it can be machined in the annealed or age hardened condition with the proper selection of tool materials, speeds, feeds, and coolants. Due to the strength and hardness of Inco X750, any rough machining should be performed prior to precipitation hardening.
Welding
Inconel X750 has good welding capabilities, especially when combined with gas tungsten arc (GTA), plasma arc, and electron beam welding. Inconel 718 weld filler is the preferred choice to help resist strain age cracking. Welding is usually performed on solution annealed material with appropriate post weld heat treatment to obtain the desired properties. Precipitation hardened alloys are also weldable, but weld joints are susceptible to cracking and will be relatively soft and brittle until heat treated. A complete post weld solution, annealing, and precipitation heat treatment is usually used to obtain the best properties of the weldment.
Forming
Inconel X-750 has fair to good forming results in the solution annealed condition. Due to its rapid strain hardening rate, frequent in-process anneals are required when complex shapes are required.
Corrosion Resistance
Inco X750 has good resistance to general corrosion and stress corrosion over a wide temperature range in both oxidizing and reducing conditions.
