| 摘要 |
PURPOSE:To improve the toughness in the root part in welding of thick plates by using a baked flux having a specific compsn. in one side submerged arc welding with multiple electrodes and increasing the content of Mn in the wire compsn. to be used for the 1st electrode. CONSTITUTION:A baked flux contg. 10-40% MgO basing on the entire part of the flux, 4-20% TiO2, 3-25% SiO2, 0.2-1.0% B2O3, 0.5-5% Mn and if necessary 0.3-3.0% Mo is used in one side submerged arc welding of thick plates with multiple electrodes. A wire contg. 2.3-3.5% Mn or 1.5-3.5 Mn and 0.1- 1.0 Mo is used for at least the 1st electrode. The toughness in the root part in the one side submerged arc welding of a low temp. steel such as aluminum killed steel and controlled rolled steel or the like is assured by the above-mentioned welding method. The method is particularly effective in the one side submerged arc welding between large electrodes in which the weld zone is thoroughly separated to two molten pools. |
