| 摘要 |
PURPOSE:The captioned welding rod of good impact toughness such as Charpy and crack opening displacement amount (COD value) which is obtainable by adding respectively suitable amounts of Mn and B to the core wire and Ti and further one or more kinds of Al, Mg, Zr and Ca to the coating agent. CONSTITUTION:The low alloy steel core wire which contains Mn; 1.6-2.4%, B; 0.004-0.02% as essential components and further N; 0.006% or less is prepared. Next, the coating agent composed of Ti; 0.5-8%, total of one or more kinds of Al, Mg, Zr and Ca; 0.2-8%, Si; 1-8%, total of one or more kinds of CaCO3, MgCO3 and BaCO3; 7-58%, total of one or more kinds of CaF2, MgF2, AlF3, Na3AlF6; 1-30% and the rest of slag forming agent, arc stabilizing agent and binder is coated around this core wire. If welding is done by using the low hydrogen type coated electrode obtainable as a result of this, then the weld metal of good imact toughness at low temperature and COD value may be obtained and contribution made to the stability of low temperature tanks or other structures. |
