For Extremely Corrosive Environments

Ultra

The Ultra range includes highly alloyed austenitic grades that are designed for extremely corrosive environments with PRE of more than 27.

The Ultra range includes our key products Ultra Alloy 825 (EN 2.4858), Ultra 904L (EN 1.4539) and Ultra 254 SMO (EN 1.4547) as well as several alternatives, for example Sanicro® 35. 

The Ultra range is the best choice when you need material for extremely corrosive environments where standard grades like Core 304L/4307 or Supra 316L/4404 are not sufficient for the corrosion challenges of your application. 

The Ultra range stainless steels are not just excellent in corrosion resistance, but the strength and elongation properties of the Ultra range are similar or better in comparison with conventional austenitic stainless steels. The addition of nitrogen to Ultra grades such as Ultra 254 SMO gives them higher yield and tensile strength. Despite the greater strength of these steels, they offer very good possibilities for cold as well as hot forming. Ultra range steels are well suited for welding, and the methods used for welding conventional austenitic steels can also be used on these products.

Typical applications for Ultra range grades are:

  • chemical and petrochemical industry
  • maritime exhaust gas cleaning
  • heat exchangers
  • applications requiring resistance for chlorinated seawater.

Ultra Alloy 825 is a Ti-stabilized austenitic nickel base alloy used in the oil and gas industry in piping systems, petroleum refinery equipment and sour gas service systems. Ultra 904L is used in petrochemical industry equipment such as pipes, heat exchangers, tanks, and reactor vessels. Ultra 254 SMO is for applications requiring resistance to chlorinated seawater, flue gas cleaning, maritime exhaust gas cleaning as well as bleaching equipment in the pulp and paper industry and flanges and valves.

Ultra range grades can be used in a wide range of applications supported with a broad selection of surface finishes from mills and service centers.

Outokumpu Ultra grades

Ultra 904L stainless steel

Ultra 904L is a high-nickel and molybdenum austenitic stainless steel with very high corrosion resistance. It was originally developed for handling sulfuric acid at ambient temperatures, and is now used in a broad range of chemical industry applications.

Please remove item from comparison before you can add another one

  • EN: 1.4539
  • ASTM type: 904L
  • ASTM UNS: NO8904
  • Microstructure: Austenitic
Typical applications
  • Chemical and petrochemical industry equipment such as pipes, heat exchangers, tanks, and reactor vessels
  • Sulfuric acid handling
  • Flanges and valves
Product forms
Typical chemical composition, % by mass
  • C: 0.01
  • Cr: 19.8
  • Ni: 24.2
  • Mo: 4.3
  • N: -
  • Others: 1.4Cu

Ultra 254 SMO stainless steel

A 6 % molybdenum and nitrogen-alloyed austenitic stainless steel with extremely high resistance to both uniform and localized corrosion. This product was developed especially for oil and gas offshore platforms and the pulp and paper industry.

Please remove item from comparison before you can add another one

  • EN: 1.4547
  • ASTM type: -
  • ASTM UNS: S31254
  • Microstructure: Austenitic
Typical applications
  • Applications requiring resistance to chlorinated seawater
  • Flue gas cleaning
  • Maritime exhaust gas cleaning (EGC)
  • Bleaching equipment in the pulp and paper industry
  • Flanges and valves
Product forms
Typical chemical composition, % by mass
  • C: 0.01
  • Cr: 20.0
  • Ni: 18.0
  • Mo: 6.1
  • N: 0.20
  • Others: Cu

Ultra 317L stainless steel

Ultra 317L is a molybdenum-alloyed austenitic stainless steel with higher corrosion resistance than Supra 316L/4404 – mainly used in the USA and Asia.

Please remove item from comparison before you can add another one

  • EN: 1.4438
  • ASTM type:

    317L

     

  • ASTM UNS: S31703
  • Microstructure : Austenitic
Typical applications
  • Chemical processing industry
Product forms
Typical chemical composition, % by mass
  • C: 0.02
  • Cr: 18.2
  • Ni: 13.7
  • Mo: 3.1
  • N: -
  • Others : -

Ultra 725LN stainless steel

Ultra 725LN is a type 310 material (high chrome and high nickel) that has been developed and optimized specifically for urea production, which demand extremely high corrosion resistance. It has similar general pitting resistance to Ultra 904L.

Please remove item from comparison before you can add another one

  • EN: 1.4466
  • ASTM type: -
  • ASTM UNS: S31050
  • Microstructure: Austenitic
Typical applications
  •  Urea applications
Product forms
Typical chemical composition, % by mass
  • C: 0.01
  • Cr: 25.0
  • Ni: 22.3
  • Mo: 2.1
  • N: 0.12
  • Others: -

Ultra 6XN stainless steel

Ultra 6XN is a 6 % molybdenum, high-nickel and nitrogen-alloyed austenitic product with extremely high resistance to both uniform and localized corrosion.

Please remove item from comparison before you can add another one

  • EN: 1.4529
  • ASTM type: -
  • ASTM UNS: N08926/N08367
  • Microstructure: Austenitic
Typical applications
  • Applications requiring resistance to chlorinated seawater
  • Flue gas cleaning
Product forms
Typical chemical composition, % by mass
  • C: 0.01
  • Cr: 20.5
  • Ni: 24.8
  • Mo: 6.5
  • N: 0.20
  • Others: Cu

Ultra 654 SMO stainless steel

Ultra 654 SMO is the most corrosion-resistant stainless steel in the world. A 7 % molybdenum, very high nitrogen alloyed austenitic product with high mechanical strength. A potentially lean alternative to traditional wet-corrosion resistant nickel-based alloys.

Please remove item from comparison before you can add another one

  • EN: 1.4652
  • ASTM type: -
  • ASTM UNS: S32654
  • Microstructure: Austenitic
Typical applications
  • Pressurized and erosive systems handling chlorinated seawater at higher temperatures
  • Plate heat exchangers
  • Flue gas cleaning applications
Product forms
Typical chemical composition, % by mass
  • C: 0.01
  • Cr: 24.0
  • Ni: 22.0
  • Mo: 7.3
  • N: 0.50
  • Others: 3.5Mn Cu

Sanicro® 35 nickel base alloy

Sanicro® 35 is the latest addition to the Outokumpu Ultra range bridging the gap between high performance stainless steel and conventional nickel base alloys. This new grade has excellent corrosion resistance in combination with high mechanical strength. Due to its leaner alloying concept Sanicro® 35 can be an attractive and cost competitive alternative to nickel base alloys with similar properties.

Please remove item from comparison before you can add another one

  • W. Nr: -
  • UNS: N08935
  • ISO: -
  • Microstructure: Austenitic
Sanicro®35 in a nutshell
  • Excellent resistance to pitting and crevice corrosion
  • Excellent resistance to stress corrosion cracking (SCC)
  • Very suitable in seawater applications
  • High resistance to uniform corrosion in acid and caustic environments
  • High resistance to erosion-corrosion
  • Very high mechanical strength
  • Good fabrication properties such as forming and welding

Sanicro® is a trademark owned by Alleima AB

Typical applications
  • Heat exchangers
  • Equipment in oil refineries
  • Equipment in biorefineries
  • Equipment in chemical process industry
  • Seawater and brine handling equipment

 

Product forms

Typical chemical composition, % by mass
  • C: 0.02
  • Cr: 27.0
  • Ni: 35.5
  • Mo: 6.4
  • N: 0.27
  • Others : Cu

Ultra Alloy 825 nickel base alloy

Outokumpu Ultra Alloy 825 is a titanium stabilized austenitic nickel base alloy with an addition of copper.

Please remove item from comparison before you can add another one

  • W.-Nr.: 2.4858
  • UNS: N08825
  • ISO: NW8825/ NiFe30Cr21Mo3
  • Microstructure: Austenitic
Typical applications
  • Components in sour gas service
  • Offshore oil and gas piping systems
  • Equipment in petroleum refineries
  • Heating coils
  • Heat exchangers
  • Tanks
  • Scrubbers
  • Chemical processing equipment
  • Food process equipment
  • Nuclear industry equipment
Product forms
Typical chemical composition, % by mass
  • C: 0.01
  • Cr: 23.0
  • Ni: 39.0
  • Mo: 3.2
  • Cu: 1.7
  • Others: Ti 0.75, Mn 0.8, Si 0.35, Al 0.1, Fe bal.

Standards and approvals for Ultra range

 EN 10028-7   Flat products for pressure purposes – Stainless steels
 EN 10088-2  Stainless steels – Corrosion resisting sheet/ plate/strip for general and construction purposes
 EN 10088-3  Stainless steels – Corrosion resisting semi-finished products/bars/rods/wire/sections for general and construction purposes
 EN 10088-4   Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for construction purposes 
 EN 10088-5  Technical delivery conditions for bars, rods, wire, sections and bright products of corrosion resistant steels for construction purposes
 EN 10272  Stainless steel bars for pressure purposes 
 EN 10283  Corrosion resistant steel castings

 The most commonly used international product standards are given in the table above. For a full list of standards by product, visit Steel Finder. 

 ASTM A 193 / ASME SA-193   Alloy and stainless steel bolts and nuts for high pressure and high temperature service 
 ASTM A 240 / ASME SA-240  Cr and Cr-Ni stainless steel plate/sheet/strip for pressure purposes
 ASTM A 276  Stainless and heat-resisting steel bars/shapes
 ASTM A 312 / ASME SA-312  Seamless and welded austenitic stainless steel pipe
 ASTM A 351 / ASME SA-351  Steel castings, austenitic, duplex for pressure containing parts
 ASTM A 358 / ASME SA-358  Electric fusion-welded austenitic Cr-Ni alloy steel pipe for high temperature 
 ASTM A 409 / ASME SA-409  Welded large diameter austenitic pipe for corrosive or high-temperature service
 ASTM A 473  Stainless steel forgings for general use 
 ASTM A 479 / ASME SA-479  Stainless steel bars for boilers and other pressure vessels
 ASTM A 743  Castings, Fe-Cr-Ni, corrosion resistant for general application
 ASTM A 744  Castings, Fe-Cr-Ni, corrosion resistant for severe service
 ASTM B 649 / ASME SB-649   Bar and wire

 The most commonly used international product standards are given in the table above. For a full list of standards by product, visit Steel Finder.

 NACE MR0175    Sulfide stress cracking resistant material for oil field equipment 
 Norsok M-CR-630  Material data sheets for 6Mo stainless steel
 VdTÜV WB 473  Austenitischer Stahl X 1 CrNiMoCuN 20 18 7 Werkstoff-Nr. 1.4547
 VdTÜV WB 537  Stickstofflegierter austenitischer Stahl X2CrNiMnMoN 25-18-6-5 Werkstoff-Nr 1.4565

 The most commonly used international product standards are given in the table above. For a full list of standards by product, see steelfinder.outokumpu.com

 

  • AD 2000 Merkblatt
  • Approval of Material Manufacturers
  • Factory Production Control Certificate
  • ISO 9001
  • ISO 14001
  • ISO 50001
  • ISO/TS 16949
  • NORSOK
  • OHSAS 18001
  • Pressure Equipment Directive (PED) 

For the list of certificates and approvals by mill, see outokumpu.com/certificates

Ultra range use cases and articles

View all

Article

What if you understood stainless properties from the name?

Article

Ultra Alloy 825 hits the sweet spot for the oil and gas industry

Case Jyväskylä power station

Expertise for extreme conditions

White paper

Selecting a suitable Ultra grade for highly corrosive applications

Article

Case Oil Platforms - When corrosion is not an option

Article

Stainless steel for hydrogen storage tanks

Article

New lean alternative to nickel-based alloys

Article

Outokumpu ready to roll out high-performance Sanicro® 35 corrosion-resistant alloy

Webinar

Meeting the material challenges of Oil and Gas corrosion

Outokumpu Ultra range downloads

Outokumpu Ultra range datasheet
Download
Outokumpu Product Ranges chart
Download
Machining guidelines for high-alloy-superaustenitic stainless 654 SMO®
Download
Machining guidelines for high alloyed superaustenitic stainless steel 254 SMO®
Download
Machining guidelines for standard austenitic stainless steel grades
Download