CD3MCUN Duplex Stainless Steel


A890 1C CD3MCUN overview

CD4MCUN duplex stainless steel casting is widely used in various industries. It is duplex stainless steel, which means that it has a ferritic and austenitic microstructure.

Thanks to its two-phase microstructure, ASTM A890 CD3MCUN Grade 1C Duplex Stainless Steel has excellent mechanical properties. Its yield strength is twice that of conventional austenitic stainless steel, and its ultimate tensile strength is also much higher. In addition, it has good fatigue strength, superior stress corrosion cracking resistance, and excellent impact resistance, even at low temperatures.
It also has excellent corrosion resistance, thanks to its high chromium and molybdenum content. This alloy is resistant to a wide range of corrosive environments, including chloride-containing media, such as seawater and salt spray.

The characteristics of duplex stainless steel CD3MCUN

CD3MCUN is duplex stainless steel that combines the benefits of both austenitic and ferritic stainless steels, offering corrosion resistance and strength.

  • Its enhanced strength makes it suitable for applications with high mechanical stress, such as tanks, pipelines, and structural components.
  • Its superior resistance to chloride-induced localized pitting and crevice corrosion makes it suitable for use in industrial applications such as chemical processing, pharmaceuticals, and offshore oil and gas platforms.
  • Its increased strength gives it greater resistance to fatigue cracking and greater weldability than other types of stainless steel.

Application of A890 Grade 1C

Duplex stainless steel CD3MCUN is an alloy that offers a unique combination of mechanical properties and enhanced corrosion resistance.

  • It is commonly used in applications that require high strength and corrosion resistance such as marine and chemical processing equipment, piping, tanks, and valves.
  • It is also used in industrial and automotive components, such as fasteners, valves, and pumps.  Its superior mechanical properties are achieved through its high amounts of chromium, molybdenum, and nickel. 
  • It is also highly resistant to stress corrosion cracking, pitting, and crevice corrosion, making it ideal for extreme environments. 

A890 gr 1C material equivalent

ACI-ASTM CD3MCuN steel is an advanced alloy formulated for the casting process, classified under both the American Concrete Institute (ACI) and American Society for Testing and Materials (ASTM) systems as CD3MCuN. It has an ASTM designation of A890 Grade 1C, and its UNS number is J93373. This duplex stainless steel is widely recognized for its excellent corrosion resistance, hardness, durability, strength, and exceptional formability.

Related standards

Material Composition

Physical Properties

Carbon:                                                      0.03%MAX

Manganese:                                                1.2%MAX

Silicon:                                                         1.1%MAX

Phosphorus:                                             0.03%MAX

Sulfur:                                                        0.03%MAX

Chromium:                                               24.0–26.7%

Nickel:                                                           5.6–6.7%

Molybdenum:                                              2.9–3.8%

Copper:                                                    1.40–1.90%

Nitrogen:                                                  0.22–0.33%


Cited properties of materials are suitable and applicable for both the normalized and tempered conditions.

Tensile strength, ksi[MPa], min                            100[690]

Yield strength (0.2% offset), ksi[MPa], min         65[450]

Elongation in 2 in.(50mm), %                                  25 

Cd3mcun Duplex stainless steel
Cd3mcun Duplex stainless steel

Heat Treatment

A890 Grade 1C CD3MCUN Duplex Stainless Steel can be heat treated to improve its mechanical properties. The heat treatments include solution annealing, aging, and stress relieving. Solution annealing is done at a temperature of 1050-1100°C . Aging is done at a temperature of 650-750°C . Stress relieving is done at a temperature of 500-650°C .


A890 Grade 1C CD3MCUN Duplex Stainless Steel is an austenitic-ferritic stainless steel that is highly resistant to corrosion and has excellent mechanical properties. It is composed of iron, chromium, nickel, molybdenum, nitrogen, and copper. The alloy is specified in the ASTM A890 standard and is widely used in the production of pressure vessels, piping, and valves. It is also used in the manufacturing of heat exchangers, nuclear fuel elements, and power plants. The alloy is highly resistant to pitting and crevice corrosion and has good weldability. It can also be heat treated to improve its mechanical properties.