| 摘要 |
PURPOSE:To prevent generation of low temp. cracking in weld metal owing to hydrogen, by contg. no magnesite in a flux to be used for narrow groove submerged arc welding of high strength ultra thick steel thereby forming a clacined type flux of extra low hydrogen. CONSTITUTION:A flux having the following compsn. is used as a flux which decreases content of diffusible hydrogen in deposited metal and decreases defects such as low temp. cracks in the stage of narrow groove submerged arc welding of high strength ultra thick steel: A flux contg. 5-25% dolomite, 7- 18% CaF2, 3-15% Al2O3, 6-25% SiO2, 5-20% BaO (including BaCO3 in terms of oxide), <10% CaO (including CaCO3 in terms of oxide), 20-50% MgO (including MgCO3 in terms of oxide), <5% Mn, <5% Si, LiSiO2 or a mixture of 1 or 2 kinds of LiSiO2, K2SiO2 and Na2SiO2 as a binder and contg. no magnesites. |
