| 摘要 |
PURPOSE:To improve the shieldability of slag and regeneration of an arc by specifying the ratio of TiO2 and iron powder with respect to (CaCO3+MgCO3) and the content of CaF2 and org. material in the compsn. of a coating material for a covered electrode. CONSTITUTION:A coating material contg., by weight %, 15-30% SiO2, 8-30% TiO2, 2.5-11% >=1 kind among CaCO3 and MgCO3, where the ratio of TiO2/ (CaCO3+MgCO3) is 1-3.5, and further contg. 0.1-3.5% CaF2, 5-15% (FeO+ Fe2O3), 0.5-5% MnO2 and 5-15% Fe-Mn and contg. 15-40% iron powder, 2-8 iron powder/(CaCO3+MgCO3) and further 3.5-8.5% org. material (starch, etc.) is prepd. A binder such as water glass or the like is added at about 15- 23% to such covering material and is coated on a mild iron core wire, by which the covered electrode having the considerably improted elongation rate of the weld bead is obtd. |
