Alloy Grade UNS: HC – Resists Oxidation

  • Overview

    HC, also known as MTEK 29-4, is a specialized alloy primarily prized for its exceptional resistance to oxidation and high-sulfur flue gases, making it well-suited for challenging environments where these factors are a concern. While its mechanical properties are limited, restricting it to low-stress applications, its high chromium content (up to 30%) contributes significantly to its oxidation and corrosion resistance. With a service limit of 1200 degrees Fahrenheit (650 degrees Celsius), HC maintains its integrity and resists degradation even under prolonged exposure to heat and corrosive gases. This combination of properties makes HC a valuable choice for specialized applications where oxidation and corrosion resistance are paramount, even if high strength is not a primary requirement.

  • Typical Uses

    Flue gas, furnace fixtures, gas dampers, recuperator tubes, salt pots, support skids, tuyeres.

  • MetalTek Grade

    MTEK 29-4

  • Poured At:

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

Similar Specifications

Cast UNS: J92605

Cast Grade: HC

Cast ASTM: A297

Typical Chemical Composition (% by wt.)

Aluminum: n/a

Carbon: 0.5

Chromium: 26-30

Manganese: 1

Iron: n/a

Copper: n/a

Nickel: 4 MAX

Lead: n/a

Tin: n/a

Silicon: 2

Zinc: n/a

Minimum Mechanical Properties

Tensile, ksi

0

Tensile, MPa

0

Calculated PREn (Minimum)

0

Heat Treatment: Not Heat Treated

Frequently Asked Questions

Heat resistant stainless steel refers to alloys designed to maintain mechanical properties and resist oxidation at elevated temperatures.

Applications include furnace parts, heat exchangers, and components in petrochemical plants.

Heat resistant stainless steels can withstand temperatures up to 1,150°C (2,100°F), depending on the grade and exposure time.

High chromium and nickel contents stabilize the austenitic structure and form a protective oxide layer, resisting scale and oxidation.

Explore Other Alloys

Gears

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.
Stainless Steel Parts

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%.
Petrochemical Fittings

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.