Effect of E8010-P1 electrode composition on the weld metal properties

• Mn and Mo resulted in formation of acicular ferrite in the weld metal.
• Composition of E8010-P1 has significant effect on the structural and mechanical properties of weld area.
• Optimal chemical composition of pipe line E8010-P1 was determined.

Different manufactures produce E8010-P1 electrode with different chemical compositions due to the relatively wide range of permissible alloying elements in the composition of this electrode. Four groups of E8010-P1 electrodes, with different compositions, were selected and effect of electrode composition on the microstructure and mechanical properties of weld meal were examined. Microstructural studies revealed that presence of the Mn, Mo and Ni in the weld metal influences significantly on the morphology of ferrite in the weld metal zone. Large amount of Mn (around 1%) in the weld metal leads to the formation of fine acicular ferrite in the weld metal. Furthermore, presence of Mo (around 0.4%) in the weld metal prevents formation of continuous grain boundary ferrite in the weld zone. Mechanical properties investigations reveal that the more acicular ferrite in the weld metal, the higher strength and ductility of this zone.