Submerged arc welding of nickel steels - providing very high notch impact toughness at low temp., esp. for gas storage vessels

摘要

Submerged arc welding is used for steel contg. nickel, via a welding electrode wire and flux. Wire is a mild steel tube with a core contg. as a % of total electrode wt. 5-25% CaF2, 2.5-5.5% Ni, 0-0.5% Mo and 0-0.5% Ti. Flux is a bonding type contg. 10-30% SiO2, 8-20% Al2O3, 25-45% MgO, 10-30% CAO, 7-20% CaF2, plus 0-0.6% Si added as Si, Fe-Si and/or Fe-Si-Mn; and the basicity of the flux is over 1.5, where basicity = (CaO+MgO)/(SiO2 + Al2O) calculated on the wt. Used to obtain high impact toughness at very low temps. esp. in mfg. vessels for storing liq. gases e.g. N2 or O2.