Avesta 347/MVNB BASIC description: AVESTA 347/MVNb basic is a Nb-stabilised Cr-Ni electrode for welding Ti-stabilised steels such as ASTM 321 and 347 exposed to service temperatures exceeding 400°C. 347/MVNb basic provides better impact strength than the AC/DC type electrodes. Also used for the second layer (first layer 309 type) when cladding mild steel.