CE3MN (A890/A995 5A, J93404,) Duplex Stainless Steel

Table of Contents

1. CE3MN duplex stainless-steel overview

CE3MN (A890 5A) is a super duplex stainless steel that offers excellent corrosion resistance and mechanical properties. It belongs to the ASTM A890 standard and is commonly used in various industries, including chemical processing, oil and gas, and marine environments.


CE3MN contains a high percentage of chromium, nickel, and molybdenum, which contribute to its corrosion resistance and strength. The balanced combination of austenite and ferrite phases in duplex stainless steel provides a unique combination of properties, including good toughness, high strength, and resistance to stress corrosion cracking.


A890 Gr 5A duplex stainless steel exhibits superior resistance to pitting and crevice corrosion, making it suitable for use in aggressive environments where chlorides, acids, and other corrosive substances are present. It also offers good resistance to erosion, making it suitable for applications involving flowing fluids.


In terms of mechanical properties, CE3MN provides high tensile strength, good yield strength, and excellent impact toughness. These properties make it suitable for structural components and equipment subjected to heavy loads and harsh operating conditions.


Overall, CE3MN (A890 5A) duplex stainless steel is a reliable and versatile material that combines the advantages of both austenitic and ferritic stainless steels. Its corrosion resistance, mechanical properties, and durability make it a popular choice for various industrial applications requiring strength and resistance to corrosion.

2. Advantages and disadvantages of CE3MN (A890/A995 5A)

Advantages of CE3MN (A890/A995 5A) Duplex Stainless Steel:


  • Corrosion Resistance: CE3MN exhibits excellent resistance to corrosion, particularly in environments containing chlorides, acids, and other corrosive substances. It provides superior resistance to pitting and crevice corrosion, which makes it suitable for applications in harsh and corrosive environments.
  • Mechanical Strength: CE3MN offers high tensile strength and good yield strength, providing structural integrity and durability. It can withstand heavy loads and harsh operating conditions, making it suitable for applications where strength is crucial.
  • Toughness: CE3MN has good impact toughness, which means it can withstand sudden shocks and dynamic loads without fracturing. This property is particularly important in applications that require resistance to cracking or failure under impact or cyclic loading conditions.
  • Cost-Effective: Compared to some other corrosion-resistant alloys, CE3MN duplex stainless steel can be more cost-effective. It offers a good balance of performance, durability, and cost, making it an attractive option for various industries.

Disadvantages of CE3MN (A890/A995 5A) Duplex Stainless Steel:

  • Weldability: The duplex stainless steel can present some challenges in terms of weldability. Special care must be taken during welding to ensure proper heat treatment and minimize the risk of welding defects, such as excessive heat-affected zone (HAZ) grain growth or sensitization.
  • Design Considerations: Duplex stainless steels, including CE3MN, require careful consideration during design and fabrication. Attention must be given to issues such as thermal expansion, distortion, and stress corrosion cracking. Proper design and fabrication practices are necessary to optimize the performance and longevity of components made from it.
  • Maintenance and Repair: Duplex stainless steels may require specific maintenance and repair procedures to ensure long-term performance. For example, proper cleaning, passivation, and maintenance of chloride levels are important to minimize the risk of corrosion or premature failure.
  • Despite these considerations, CE3MN (A890/A995 5A) duplex stainless steel offers a range of advantages, especially in corrosive environments where both high strength and corrosion resistance are required. With proper design, fabrication, and maintenance, it can be a reliable and cost-effective choice for various industrial applications.

Chemical Composition and Mechanical Properties of CE3MN (A890/A995 5A)

Chemical composition

Carbon:                                                                  0.03% Max

Manganese:                                                          1.50% Max

Silicon:                                                                   1.00% Max

Phosphorus:                                                          0.04% Max

Sulfur:                                                                     0.04% Max

Chromium:                                                        24.00-26.00%

Nickel:                                                                 6.00 – 8.00%

Molybdenum:                                                   4.00 – 5.00%

Nitrogen:                                                             0.10 – 0.30%

Typical CE6MN microstructure
Typical CE6MN microstructure
CE3MN Casting pipe
CE3MN Casting pipe
Mechanical properties
  • Yield Strength:                        75 ksi Min
  • Tensile Strength:                    100 ksi
  • Elongation at 2 in:                  18% Min

A995 5A Reference Casting Standards and others

CE3MN material equivalent to

ASTM   A890/A995 5A ;UNS-Cast   J93404 ;ASME   SA890 5A; AISI:    2507 ;Type: 25Cr-7Ni-Mo-N;ACI CE3MN;UNS – Wrought:  S32750

CE3MN Casting Typical Application

 A890/A995 5A duplex stainless steel castings find application in a variety of industries and environments where corrosion resistance, strength, and durability are crucial. Some typical applications of  castings include:

  1. Chemical Processing: The castings are commonly used in chemical processing plants for equipment such as pumps, valves, impellers, and heat exchangers. The excellent corrosion resistance of CE3MN makes it suitable for handling corrosive chemicals and fluids.
  2. Oil and Gas Industry: Gr 5A is widely employed in the oil and gas sector for applications like offshore platforms, subsea equipment, valves, and pumps. Its resistance to chloride-induced stress corrosion cracking and its ability to withstand high-pressure and corrosive environments make it suitable for such applications.
  3. Desalination Plants: A995 Gr 5A is utilized in desalination plants where seawater is converted into freshwater. The material’s resistance to chloride corrosion and its mechanical strength make it suitable for components such as pumps, valves, and heat exchangers in the desalination process.
  4. Marine and Shipbuilding: Due to its superior corrosion resistance in marine environments, A890 5A castings are utilized in marine applications including propellers, pump components, shipboard equipment, and offshore structures.
  5. Water Treatment: It is employed in water treatment facilities for components such as pumps, valves, and filters. Its corrosion resistance and strength make it suitable for handling various chemicals and wastewater.
  6. Pulp and Paper Industry: The castings are used in the pulp and paper industry for equipment such as pumps, valves, and agitators. The material’s resistance to corrosion from chemicals and high temperatures is beneficial in the harsh processing conditions of this industry.
  7. Mining and Mineral Processing: It is utilized in mining and mineral processing equipment where resistance to abrasive slurries and corrosive chemicals is required. Examples include slurry pumps, valves, and hydro cyclones.

It’s important to note that specific application requirements and environmental conditions may influence the suitability of The castings. Consulting with engineers and experts in the respective industries is recommended to ensure proper material selection and performance.

J93404 Casting Heat treatment process

The recommended heat treatment process for castings involves the following steps:

  • Heat the casting to a minimum temperature of 2050°F (1120°C).
  • Maintain this temperature for a sufficient duration to ensure the entire casting is heated uniformly.
  • Allow the casting to cool in the furnace until it reaches a minimum temperature of 1910°F (1045°C).
  • After reaching the minimum temperature, the casting should be rapidly cooled by quenching it in water or employing other suitable rapid cooling methods.

Please note that specific heat treatment procedures may vary depending on the size, shape, and specific requirements of the castings. It is advisable to consult the manufacturer’s recommendations or seek guidance from qualified experts for precise heat treatment instructions for your castings.