Creep Resisting 9CrWV (P92) Sub-Arc Wire.
Applications
These consumables are designed to weld equivalent ‘type 92’ P92 9%Cr steels modified with tungsten, vanadium, niobium, nitrogen and a small addition of boron to give improved long-term creep properties. They are specifically intended for high-integrity structural service at elevated temperatures so the minor alloy additions responsible for its creep strength are kept above the minimum considered necessary to ensure satisfactory performance. In practice, weldments will be weakest in the softened (inter-critical) HAZ region of the parent material, as indicated by so-called ‘type IV’ failure in transverse weld creep tests. The rupture strength of P92 is up to 30% greater than P91, and interest in its use is growing as a candidate for components such as headers, main steam piping and turbine casings, in fossil-fuelled power generating plants.