Filled wire for arc welding mild or lightly alloyed steel - used at high currents and deposition rate without formation of projections on the weld

摘要

Wire comprises a sheath of mild or lightly alloyed steel filled with 30-60g/100 g sheath with a mixt. of Fe powder together with slag forming elements, metallic deoxidisers, and arc stabilisers. Before charging into the wire, the powder is treated with soluble or atomised silicates and heated for >=3 hrs. at 600 degrees C. Specif. the powder comprises (by wt.): 50-85% Fe (=10% substd. by Ni, Mo and/or Cr), 4-8% FeSi (45% Si) (=7% substd. by CaSi), 4-8% FeMn refined, 10-20% CaF2 (=10% substd. by NaF), 0.6% CaCO3 (=5% substd. by other alkaline earth carbonates or MgO), 0-2% SiO2 or Al2O3 or K felds par, and 0-2% K titanate. The powder is aggregated with 4-10g/100g of soluble alkaline earth silicate, or simply mixed with 1-3g% atomised silicate of -100 mesh.