Oxygen and Nitrogen contents of Multilayer Weld Metal by Submerged Arc Welding

This study was made on the oxygen and nitrogen contents and notch toughness of the multilayered weld metal produced by submerged arc welding.The results obtained are summarized as follows.(1) The oxygen content of multilayered weld metal increased as the number of layered weld metal increased.(2) The nitrogen content of multilayered weld metal is almost constant irrespective of the number of layered weld metal.(3) The silicon content of multilayered weld metal increased as the number of layered weld metal increased, and the oxygen content of multilayered weld metal shows the similar tendency.(4) The manganese content of multilayered weld matal increased by MnO included flux, and decreased by flux without MnO as the number of layered weld metal increased.(5) The carbon content of multilayered weld metal decreased as the number of layered weld metal increased.(6) The impact value of multilayered weld metal is roughly constant, but the value of last layered weld metal decreased slightly.(7) The oxygen and nitrogen contents of weld metal does not change remarkablly irrespective of heat treatment.(8) The oxygen content of weld metal increased as the welding current increased, but the nitrogen content in weld metal decreased as the welding current increased, and the impact value of weld metal generally decreased as the welding current increased.