UNS N06601 Inconel Round Bars DIN 2.4851

Product Description

UNS N06601 (popularly known as Inconel 601 / DIN 2.4851 / NiCr23Fe) is a general-purpose nickel-chromium superalloy that excels at a single, critical engineering metric: extreme resistance to high-temperature oxidation and spalling.

While Inconel 625 is the go-to choice for severe aqueous/marine corrosion, Inconel 601 is engineered primarily for thermal processing environments. It retains structural stability and oxidation resistance at temperatures reaching up to 1180C (2150F).

The Aluminum Advantage: Mechanism of Resistance

The defining metallurgical trait of UNS N06601 is the deliberate addition of 1.0% to 1.7% Aluminum.

When exposed to elevated temperatures, this aluminum reacts with the environment alongside chromium to form an extremely tightly adherent, protective interlocking oxide scale. This passive film resists "spalling" (flaking off under rapid thermal cycling), protecting the underlying metal from catastrophic oxidation, carburization, and nitriding atmospheres.

Technical Specifications & Global Equivalents

Chemical Composition (Weight %)

• Nickel (Ni): 58.0 63.0% (Provides a highly stable austenitic matrix)

• Chromium (Cr): 21.0 25.0% (Forms primary high-temperature passivation)

• Aluminum (Al): 1.0 1.7% (Forms interlocking oxide scale)

• Iron (Fe): Balance (~14.0% 18.0%)

• Manganese (Mn): 1.0% Maximum

• Silicon (Si): 0.5% Maximum

• Carbon (C): 0.10% Maximum

Round Bar Supply Conditions & Dimensional Range

UNS N06601 round bars cannot be hardened via heat treatment; they are strengthened through solid-solution mechanisms and cold working. Bars are typically delivered in the solution-annealed condition to maximize creep-rupture ductility at service temperatures.

• Size Configurations: Available from small-diameter precision drawing wire and ground rods (3 mm) up to heavy-duty forged structural shafts (250 mm+).

• Surface Finishes: Black hot-rolled/forged, peeled/rough turned, or high-accuracy centerless bright ground.

• Geometries: While round bars are the dominant stock profile, square bars, hex bars, and flat shapes are routinely processed for structural frame fabrication.

Mechanical & Physical Properties (Typical Solution-Annealed)

• Density: $8.11 \text{ g/cm}^3$ ($0.293 \text{ lb/in}^3$)

• Melting Range: 1360C 1411C (2480F 2571F)

• Tensile Strength: $\ge$ 550 MPa (80 ksi)

• Yield Strength (0.2% Offset): $\ge$ 205 MPa (30 ksi)

• Elongation at Break: $\ge$ 30% (Ensures high ductility during cold forming)

Primary Applications for 2.4851 Round Bars

Because of its superior mechanical strength and oxidation barrier stability at high temperatures, Inconel 601 round bars are heavily utilized for:

• Thermal Processing Hardware: Furnace baskets, fixtures, retorts, conveyor belts, muffle tubes, and radiant tubes.

• Petrochemical Plants: Catalyst grid supports, combustor components, and regenerator tubes in highly aggressive nitric acid production lines.

• Power Generation & Internal Combustion: Exhaust systems, thermal reactors, glow plug components, and gas-turbine rotor hardware.

• Pollution Control Systems: Thermal oxidizers and incinerator combustion chambers.

Fabrication, Machining, & Welding Checklist

• Machining Characteristics: Hard and work-hardens rapidly. It requires high-torque, rigid setups, heavy constant feed rates, and specialized carbide tooling. It should ideally be machined in the solution-annealed state.

• Welding Profile: Features excellent weldability. It can be joined easily using Gas Tungsten Arc Welding (GTAW) or Shielded Metal Arc Welding (SMAW).

• Filler Metal Selection: For service temperatures below 900C, matching Inconel Filler Metal 601 (ERNiCrFe-11) is perfect. However, if the components will be running continuously above 900C (1650F), engineers often switch to Inconel Filler Metal 617 or 625 to ensure the weld metal matches or exceeds the high creep-rupture requirements of the base metal.