A Guide to Inconel CNC Machining

Key Takeaways

• Inconel® delivers exceptional heat resistance, corrosion resistance, and strength in extreme environments up to around 700°C (1292°F).

• Different Inconel grades are optimized for demanding industries such as aerospace, energy, chemical processing, and marine applications.

• Inconel is a difficult-to-machine alloy that requires specialized tooling and machining techniques to achieve high-quality results.

Overview

Inconel® is a nickel-based alloy known for its exceptional strength and corrosion resistance in high-temperature environments. It consists primarily of nickel, with iron, chromium, niobium, and other elements. The chromium forms a strong passive film on the surface, providing excellent corrosion resistance. Inconel retains its strength at temperatures up to around 700°C (1292°F). However, it is classified as a difficult-to-machine material, posing challenges for cutting and CNC machining.

Characteristics of Inconel

High Heat Resistance

Inconel maintains its strength at temperatures around 700°C (1292°F). In contrast, stainless steel typically withstands only up to 500°C (932°F). While most metals lose significant strength at high temperatures, Inconel resists this degradation, classifying it as a super heat-resistant alloy. This property makes it ideal for aerospace and industrial applications exposed to extreme heat.

High Corrosion Resistance

Inconel resists corrosion even in high-temperature environments up to approximately 1000°C (1832°F). Chromium and other elements form a protective oxide film on its surface, similar to stainless steel. It also resists water, acids, alkalis, and other corrosive agents, minimizing rust and degradation in harsh conditions.

Difficult to Machine

Inconel is challenging to machine due to work hardening, which is where hardness increases when external force is applied. Additionally, its low thermal conductivity concentrates heat on cutting tools, accelerating wear and complicating machining. Machining Inconel requires careful control of cutting conditions, tools, and cooling methods.

Types of Inconel

Inconel 600

Characteristics

• Excellent oxidation resistance at high temperatures.

• Resists stress corrosion cracking caused by chloride ions.

• Resistant to many oxidizing and reducing organic acids.

• Excellent corrosion resistance against alkalis and complete resistance against ammonia.

Applications

• Water treatment equipment

• Industrial furnaces

• Aircraft exhaust systems

• Evaporator materials

• Ammonia plants

• Electronic components.

Inconel 625

Characteristics

• Resists pitting, crevice corrosion, and intergranular corrosion.

• Maintains high fatigue strength under high temperature conditions.

Applications

• Nuclear waste treatment equipment

• Supercritical water systems

• Seawater components

• Pollution control equipment.

Inconel 718

Characteristics

• Good manufacturability in the annealed state, with excellent tensile strength, fatigue strength, and creep rupture strength.

• Maintains high strength up to 700°C (1292°C)

• Excellent oxidation resistance up to 1000°C (1832°C).

• Performs well under cryogenic conditions

• Resists corrosion under both low and high temperatures.

• Resists stress corrosion cracking and pitting, and does not crack after arc welding or resistance welding processes.

Applications

• Turbine disks

• Gas turbines

• Rotating and stationary parts of rocket engines

• High-strength bolts and springs

• Nuclear reactor and spacecraft components

• Pump shafts

• Wellhead equipment

• Oilfield tools

• Drilling equipment.

Inconel X-750

Characteristics

• A precipitation hardened nickel-chromium alloy with excellent corrosion resistance, oxidation resistance up to about 700°C (1292°C).

• High tensile strength and resists relaxation (creep deformation).

Applications

• Gas turbines

• Nuclear reactor components

• Pressure vessels

• Heat-resistant springs

• Fasteners

Inconel CNC Machining at Yumoto Electric

Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of metals using milling, turning, and specialized metal processing. We have experience with over 200 materials including aluminum alloys, stainless steel, molybdenum, and titanium. 

If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.