Metrode Ultramet-309NB description: Ultramet 309Nb is designed specifically for use where niobiumstabilised weld metal is required in overlays, or inlays, on CMn or low alloy steels. A minimum niobium content of 0.7% in undiluted weld metal ensures a fully stabilised deposit of approximately 347 composition is produced in the first layer on mild and medium carbon steels. It may also be useful for the first run when welding 321 or 347 clad steels, prior to completion with 347 type weld metal. It is not recommended as an alternative to 309L types for dissimilar welded joints.