PURPOSE: To obtain weld matal excellent in COD value and in impact toughness such as Charpy value, by applying coating material composed on limited quantities of metallic carbonate and fluoride with caking material around core with made of carbon steel contg. respective limited quantities of O, S, and one or two of Ca, Mg.
CONSTITUTION: Core wire made of carbon steel contg. ≤0.003% O, ≤0.002% S, 0.001W0.01% one or two of Ca, Mg, is coated around it with coating material shown below by use of potassium (sodium) silicate as caking material to a covering ratio 20W55%. The above described coating material is composed of 7W58% carbonate such as CaCO 3 etc., 1W40% fluoride such as CaF 2 etc., the remainder being principally deoxidizer (e.g., Ti, Zr, etc.) and Fe.