Microstructural analysis of carbon steel after shielded metal arc welding process

The aim of this paper was to determine the microstructure and hardness of welded joint of carbon steel API 5L X52. The pipe dimension 219.1 x 5.6 mm is welded to the abutting V- joint. The root and filling passes as V-joint was performed by shielded metal arc welding (SMAW) process with electrodes type Boehler FOX CEL Mo with diameter of 2.5 and 3.2 mm. Analysis of the microstructure of welded joint was carried out by optical and scanning electron microscopy (SEM), respectively. The obtained microstructure was ferrite with less portion of pearlite. In microstructure of the weld metal regions with Widmanstatten`s ferrite was observed. The energy dispersive spectrometry (EDS) analysis showed sporadically presence of slag inclusions in the weld metal. The microhardness was measured in the base material, heat affected zone and weld metal. The hardness values of weld metal and heat affected zone were less than the base material.