Alloy Grade UNS: CN3MN – Super Austenitic Alloy

  • Overview

    CN3MN, also known as MTEK 6XN, is a super austenitic stainless steel that offers exceptional corrosion resistance, even in the most challenging environments. This alloy excels in resisting various forms of corrosion, including chloride-induced stress corrosion cracking, crevice corrosion, and pitting corrosion, making it suitable for exposure to acids, alkalis, and salt solutions. With a composition of up to 25.5% nickel and 22% chromium, CN3MN surpasses the corrosion resistance of typical austenitic stainless steels. Its enhanced resistance to localized corrosion, combined with its good mechanical properties, makes CN3MN a valuable choice for applications in chemical processing, marine environments, and other demanding industries where superior corrosion resistance is critical.

  • Typical Uses

    Pump and valve components, desalination equipment, oil & gas applications, pulp & paper rolls, and chemical processing equipment.

  • MetalTek Designation

    MTEK 6XN

  • Poured At:

    Carondelet Division, Sandusky International Division, Wisconsin Centrifugal Division, Wisconsin Investcast Division

* Patented or restricted alloys are produced under licenses from their respective owner.

Similar Specifications

Cast UNS: J94651

Wrought UNS: N08367

Wrought Grade: AL6XN®

Cast Grade: CN3MN

Cast ASTM: A743, A744

Typical Chemical Composition (% by wt.)

Aluminum: n/a

Carbon: 0.03

Chromium: 20-22

Manganese: 2

Iron: n/a

Copper: n/a

Nickel: 23.5-25.5

Lead: n/a

Tin: n/a

Silicon: 1

Zinc: n/a

Other: Mo 6-7; N 0.18-0.26

Minimum Mechanical Properties

Tensile, ksi

0

Tensile, MPa

0

Calculated PREn (Minimum)

0

Yield, ksi

0

Yield, MPa

0

Elongation

0%

Heat Treatment: Solution Anneal

Frequently Asked Questions

Super austenitic steel is a high-alloy stainless steel with enhanced levels of chromium, molybdenum, and nitrogen, providing superior resistance to chloride-induced corrosion.

Used in desalination plants, offshore platforms, chemical processing, marine equipment, and pulp & paper industries where high chloride or acidic environments are present.

Super austenitic steels offer higher molybdenum and nitrogen levels than standard austenitic steels, improving their resistance to pitting, crevice, and stress corrosion.

Benefits include exceptional resistance to aggressive environments, high strength, extended life in chloride-rich applications, and suitability for welding and fabrication.

Its high levels of molybdenum, chromium, and nitrogen promote the formation of a passive oxide layer that protects against localized and general corrosion.

Grades such as 254SMO and AL-6XN are considered super austenitic stainless steels, offering premium corrosion resistance in extreme environments.

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Non-Ferrous

Non-ferrous alloys are, literally, materials that are not iron-based. While others may provide non-ferrous materials of other materials, the MetalTek family of non-ferrous alloys are copper-based. In general, these materials deliver high strength, and excellent wear and corrosion resistance. They are often found in marine applications and also bushing, bearing, and gear environments.
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Stainless Steel

Stainless steels owe their ability to resist corrosion primarily to the presence of a passive film on their surface. Chromium is chiefly responsible for formation of the passive film. Iron ceases to rust at approximately 12% chromium content and resistance to oxidizing corrosives increases rapidly with chromium content up to approximately 20%.
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Specialty Alloys

Specialty Alloys comprise a broad group of materials that deliver properties for more demanding applications, use more exotic or expensive materials, or require special processes to manufacture. Where standard materials may not offer desired performance, specialty alloys (including those that are modified further) may be a sensible selection.