| 摘要 |
The purpose of the present invention is to provide a covered electrode that combines excellent creep characteristics with the accompanying characteristics of toughness, tempering-embrittlement properties, resistance to stress-relief cracking, and ease of use in welding. This covered electrode is characterized in that: the covering thereof contains a metal carbonate, an alkali-metal oxide, and a fluorine compound such that the CO2 in the metal carbonate constitutes 5-10% of the total mass of the covered electrode, the alkali metal in the alkali-metal oxide constitutes 0.4-2.0% of the total mass of the covered electrode, and the fluorine in the fluorine compound constitutes 1.0-5.0% of the total mass of the covered electrode; the core and/or the covering of the covered electrode contain prescribed total amounts of carbon, silicon, manganese, chromium, molybdenum, vanadium, niobium, boron, magnesium, and iron relative to the total mass of the covered electrode; unavoidable copper, nickel, titanium, aluminum, tantalum, cobalt, and tungsten impurities total no more than 0.10% of the total mass of the covered electrode; and unavoidable sulfur, tin, arsenic, antimony, lead, and bismuth impurities total no more than 0.10% of the total mass of the covered electrode. |
