What Is Inconel 601 Material?

Overview

Inconel 601 is a nickel-chromium alloy used for applications that require resistance to corrosion and heat. This nickel alloy stands out due to its resistance to high temperature oxidation, remaining highly resistant to oxidation through 2200° F. Alloy 601 develops a tightly adherent oxide scale which resists spalling even under conditions of severe thermal cycling. This nickel alloy has good high temperature strength, and retains its ductility after long service exposure. It has good resistance to aqueous corrosion, high mechanical strength, and is readily formed, machined and welded. Inconel 601’s properties make it a material of broad utility in fields like thermal processing, chemical processing, pollution control, aerospace, and power generation. However, alloy 601 is not suggested for use in strongly reducing, sulfur bearing environments.

The most important property of Inconel 601 is resistance to oxidation at very high temperatures up to 1250C. Even under severe conditions such as, cyclical heating and cooling. This is possible due to Inconel 601 having a tightly adherent oxide layer which is resistant against spalling. Resistance to carburization is good, also resistant to carbon nitriding conditions. Due to high chromium and some aluminum content, good resistance in oxidizing sulfur bearing atmospheres at elevated temperatures is demonstrated.

Nickel Inconel 601 is a member of the austenitic nickel-chromium based super alloys. It is used for applications that require extremely high resistance to heat, and very high resistance to oxidation and corrosion at higher temperatures. It has excellent mechanical properties and is easily workable with standard procedures.

Due to its plethora of positive properties, it finds use in harsh environments in different industry applications, especially in places where it is repeatedly exposed to a wide temperature range and in the presence of corrosives, such as acids. Inconel 601 nickel-chromium-iron alloy is a general-purpose engineering material for applications that require resistance to heat and corrosion. The outstanding characteristic of Inconel 601 is its resistance to high-temperature oxidation. The alloy also has good resistance to aqueous corrosion, has high mechanical strength, and is readily formed, machined, and welded.

The Composition (%) of Nickel Inconel 601

Alloy 601 (UNS N06601) is a Nickel-Chromium alloy with an addition of Aluminium for outstanding resistance to oxidation and other forms of high temperature corrosion. The composition is a face-centered-cubic solid solution with a high degree of metallurgical stability. The alloy’s nickel base, in conjunction with a substantial chromium content, provides resistance to many corrosive media and high-temperature environments. Oxidation resistance is further enhanced by the aluminum content. The limiting chemical composition of Inconel 601 is listed in Table.

What are the characteristics of Inconel 601?

Inconel 601 corrosion resistance

The Inconel 601 nickel and chromium content exhibits superior resistance to high temperature corrosion mechanisms. n particular, its resistance to oxidation at 2200 ° F(1200 ° C) is very good. The lnconel 601 offers exceptional resistance to oxidation under cyclic thermal conditions due to its chromium and aluminum content. Inconel alloy 601 superior creep rupturing strength enables its usage at industries that operate under high temperatures over an extensive period of time. It is not embrittled by constant exposure to high temperature. It also has very high fatigue strength. But the annealed material has higher fatigue strength than solution-treated material.

Inconel 601 oxidation resistance

Inconel 601 exhibits excellent resistance to oxidation at high temperatures. Inconel 601 forms a protective oxide coating that counteracts the formation of lime even under severe conditions cycically exposed to temperature. The superior oxidation resistance of lnconel 601 is related to the amount of nickel, chromium and aluminum in the alloy. During high temperature exposure, these elements form a highly protective and sticky oxide film on the surface of the material. In addition, a small amount of internal oxidation occurs and a higher chromium content in the surface oxide.

Inconel 601 hot and cold forming

The temperature range for lnconel 601 is 1600-2250 ° F(870-1230 ° C). Hot run operations with large deformations should be performed at 1900-2250 °F (1040-1230 ° C). inconel 601 has low ductility at temperatures of 1200 to 1600°F (650-870 ° C) and should not be processed in this range. light can be applied at temperatures below 1200 ° F(650° C) to improve high tensile properties. Inconel 601 is cold formed by conventional methods.

Inconel 601 heat treatment

Inconel 601 can be treated by a variety of heat treatment methods, including annealing, solution treatment and aging treatment. The annealing temperature is generally 1000-1200°C, the solution treatment temperature is generally 1150-1200°C, and the aging treatment temperature is generally 870-925°C.

Inconel 601 machinability

Inconel 601 as a ‘C’ class alloy is fairly difficult to machine. Heavy machines, sharp tools, slow speeds and deep cuts to remove the work hardened layer are needed. Inconel 601 is readily weldable by the SMAW (manual), GMAW (MIG), GTAW (TIG) and SAW processes. Preheat or post weld heat treatment are not needed. Care must be taken to avoid contamination of the weld pool. Argon is used as the shielding gas.

Applications of inconel 601

The combination of nickel (61.5 %), chromium (22.5 %), and aluminium (1.4 %) content of Inconel alloy 601 makes it a superalloy that offers excellent resistance to corrosion. Inconel alloy 601 can resist spalling even under severe thermal cycling conditions. Due to the alloys high nickel content, it is extremely resistant to chloride-ion stress-corrosion in some of the most tough environments.

With exceptional mechanical strength, Inconel alloy 601 strength level varies with the condition and form of the material. Commonly, the annealed condition is used for tensile-limited applications (temperatures below 1000°F(540°C)) and the solution-treated condition is used for rupture-limited applications (temperatures of and above 1000°F (540°C)). Under various testing conditions, Inconel alloy 601 has also shown resistance to oxidation, carburization and sulfidation.

With such beneficial properties, Inconel alloy 601 has a broad range of applications - from aerospace and pollution control to chemical processing and thermal processing. Alloy 601 also has high mechanical properties at elevated temperatures. Alloy 601 is used for industrial furnaces, radiant tubes, themocouple tubes and heat treatment equipment, baskets, muffles, retorts. Petrochemical process equipment and aircraft components.

Alloy 601 in chemical processing

The Inconel alloy 601 finds its most significant application in chemical processing. The applications for Inconel alloy 601 can be – insulating cans in ammonia reformers, catalyst support grids and combustor components in nitric acid production, heaters and condenser tubes.

Alloy 601 in aerospace

Used in blades and containment rings in gas turbines, combustion-can liners, jet-engine igniters, seals and combustors and diffuser assemblies.

Alloy 601 in power generation

The Inconel alloy 601 is also used in the power-generation industry for the ash-handling systems, grid barriers and superheater tube support.

Alloy 601 in petrochemical processing

The Inconel alloy 601 is used for air preheaters and catalyst regenerators for manufacturing polyethylene in petrochemical processing units.

Alloy 601 in thermal processing equipment

In industrial furnaces, Inconel alloy 601 is used for various applications like radiant tubes, flame shields, retorts, chain curtains, burner nozzles, strand-annealing tubes, woven-wire conveyor belt and electrical resistance heating elements. They can also be used for thermal applications like furnace generators, infrared radiant screen and thermocouple protection tubes. Industrial-thermal applications like trays, fixtures and baskets can also utilise Inconel alloy 601.

Alloy 601 in pollution control devices

Inconel alloy 601 can also be useful in the exhaust systems and thermal reactors of gasoline engines. They can also be used as pollution control devices in the combustion chambers of solid waste incinerators.