Search Results for Muslim Qasem Abdulredah

Abstract

This study is focused on the assessment of the effects of Sulphur percentage in submerged arc welded API 5L X60 steel under conditions simulated to crude oil environments on its mechanical properties and microstructure. This involved immersing welded specimens in distilled water containing high (0.3250 ml/4L distilled water) and low (0.25 ml/4L distilled water) Sulphur concentrations for four weeks, while unimmersed samples were used as controls for comparison between the two groups of samples. The related experiments were tensile test, hardness measurements, SEM and EDS analyses and XRD analysis. The most mechanically degraded was the high- Sulphur group (H-group); yield strength of 441 MPa (17% loss) and ultimate tensile strength of 506 MPa (11% loss). For the low-sulfur group (L-group), reductions were more moderate: 467 MPa and 523 MPa, respectively. Weld metal (WM) and HAZ hardness values in the H-group were 203 HB and 208 HB, respectively, while those of the L-group were 208 HB and 214 HB. The H-group created a non-protective mixed layer of acicular iron oxides and iron sulfides (FeS) with respect to the microstructural aspects, whereas the L-group developed a thin protective film of iron oxide free from sulfides. Welding parameters were investigated for their effect on the corrosion rate and mechanical properties.