Metrode Ultramet-309CF description: These consumables deposit 309 type weld metal with a controlled carbon of about 0.08% and low ferrite content. These controls are designed to increase the high temperature strength and microstructural stability for service applications above 400°C. The widely used 309L dissimilar weld metal has lower hot strength and is more prone to embrittlement during long term high temperature service for which it is not intended. The main application for this electrode is for welding steels of similar composition although some high temperature steels of dissimilar composition, such as ferritic CrAl and CrSiAl alloys are applicable.