Developed for advanced ultra-supercritical steam boiler applications in highly efficient next-generation power plants, Sanicro 25 (UNS S31035) tube grade has now achieved ASME Boiler and Pressure Vessel Code (BPVC) approval.
An austenitic stainless steel with high-temperature properties, Sanicro 25 is suitable for use at material temperatures up to 700˚C (1292˚F). Sanicro 25 combines high-creep strength, oxidation resistance and structural stability with good fabrication capability. This makes it suitable for use in superheaters and reheaters in advanced coal-fired power boilers. It is also possible to use the material in other high-temperature steam boiler applications employing different fuel types.
Higher-efficiency power stations that operate at elevated temperatures have a positive effect in significantly reducing emissions, including carbon dioxide (CO2). The material is covered under ASME code case number 2753 for Section 1 – “Rules for the Construction of Power Boilers” and 2752, Section Vlll, Division 1 – “Rules for the Construction of Pressure Vessels.” Due for publication in July, the code cases can now be applied to the use of Sanicro 25 tubes in boilers designed in accordance to the ASME BPVC rules.