Sub merging arc welding process null of fire-resistant

摘要

PURPOSE:To improve the creep rupture life by obtaining weld metal to satisfy the specific expression by combining submerged arc welding flux having specific basicity with a wire having specific composition. CONSTITUTION:The submerged arc welding flux having L=0.2-3.5 is used wherein L denotes the basicity calculated by the expression I. Further, the weld metal where the B quantity (weight ppm) in the weld metal: [B] and the Ti quantity (weight ppm) in the weld metal: [Ti] satisfy the expression II is obtained by combining the flux with the submerged arc welding wire having the specific composition wherein [B] max, [Ti] max and [O] are 3.01X10-2X[O], 0.334X[O]-10.83 and the oxygen quantity (weight ppm) in the weld metal, respectively.