Below are the most frequently asked questions about Sanicro® 25 high-alloy austenitic stainless steel.

  • What kind of material is Sanicro® 25?

    Sanicro® 25 is a high-performance austenitic tube material developed for superheaters and reheaters in advanced coal-fired power boilers for material temperatures up to around 700°C (1290°F).

  • What is the chemical composition of Sanicro® 25?

    Chemical composition (nominal), %
    Si Mn Cr Ni W Co Cu Others
    0.1 0.2 0.5 22.5 25 3.6 1.5 3.0 N=0.23
  • What are the main characteristics of Sanicro® 25?

    Sanicro 25 was designed for high strength at elevated temperatures. It has very good high-temperature oxidation resistance and steam oxidation resistance. Sanicro 25 also has very good resistance to corrosion in environments with coal ash.

    Test results indicate that Sanicro 25 has higher creep strength than any other known commercial austenitic material. Sanicro 25 is also characterized by high oxidation resistance, high structural stability and good fabricability.

  • In what conditions can the tubes be delivered?

    Tubes in Sanicro 25 can be supplied hot- or cold-worked, solution annealed and white pickled.

  • What filler metal should be used for welding of Sanicro 25®?

    As filler metal for gas-shielded arc welding, wire in Sanicro® 53 or alloy 617 mod. is recommended. Contact us for more information.

  • What approvals are available?

    The following approvals are available for Sanicro® 25:

    • European Particular Material Appraisal (PMA)
    • VdTÜV material data sheet 555, 09.2008
    • The American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Code, ASME B&PV Code Case 2753, Section I and Code Case 2752, Section VIII Division I
      • China Pressure Vessel Approval CSCBPV BV-ME-210
  • Does Sanicro® 25 have a UNS number?

    UNS number S31035 was entered in the UNS database in November 2007 with cross reference to ASTM A213 and A312.

  • What test installations have so far been made?

    In August 2004, trial tubes in Sanicro® 25 were installed in the RWE plant in Weisweiler, Germany and in the Dong Energy plant in Esbjerg, Denmark. In July 2005 this was followed by a larger installation in the E.ON plant in Scholven (project COMTES 700), Germany. Sanicro® 25 is being tested in material temperatures between 650 and 700°C (1290°F). Feedback so far is very promising.

    Company Installed Engineering company
    GKW Mannheim 2009–continuing Alstom
    Vattenfall Boxberg 2008–continuing Hitachi Power
    E.ON, Scholven (COMTES 700) 2005–2009 Hitachi Power
    Dong Energy, Esbjerg 2004–2009 Alstom
    RWE Weisweiler 2004–2008 Hitachi Power