VOLUME 13, ISSUE 3, 2022

 

Cover

Aims and Scope
Editorial Board

Volume 13, issue 3, 2022, pp.i-viii. Download Full Text (PDF)
     
     

1. Comparison of two different grades of carbon steel reinforcement in the synthetic concrete pore solution

Ahmed Kareem Abdulameer, Saheb Mohammed Mahdi

Materials Engineering Department, Mustansiriayah University, Baghdad, Iraq.

Abstract: The research aims to investigate the impact of carbon steel grade on corrosion resistance in a synthetic concrete pore (SCP) solution. For this investigation, two grades of carbon steel as specified by ASTM A615-16 were selected, GR-60 (420MPa) and GR-80 (550MPa), respectively. In this study, the open circuit potential (OCP) and Tafel polarization plots were utilized and conducted at a temperature of 24 C. In addition, the metallographic inspection was also performed for both grades. The electrochemical corrosion behavior of the two steel grades is assessed in the same (SCP) solution. The results showed that the open circuit potential of GR-80 of about (-375 mV) is nobler than GR-60 of (-385 mV), indicating the passive layer of GR-80 has better quality. In addition, the cathodic slopes of the Tafel plot for both grades are approximately equal (0.111 V/decade) for GR-80 and (0.107 V/decade) for GR-60. However, the anodic slope of GR60 (0.257 V/decade) is relatively higher than GR-80 (0.222 V/decade), indicating more iron (F++) ions dissolution for GR-60. Consequently, the findings that were obtained via the application of the mixed potential theory and Faraday's law showed that the corrosion resistance of GR-80 (0.305 μm/y) in the same environment is more than that of GR-60 (0.353 μm/y) as a result of chemical changes and variances in steel's matrix microstructural characteristics that effect on the protective oxide layer formed on the steel surface.

Volume 13, issue 3, 2022, pp.103-112.

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2. Investigation of MIG welding process parameters on welding defects and hardness of low carbon steel weld joints

Nesreen Dakhel Fahad, Marwah Mohammed Abdulridha Alkhafaji

Department of Materials Engineering, Faculty of Engineering, University of Kufa, Iraq.

Abstract: The process of metal inert gas welding is controlled by various factors. The research intends to investigate the effects of two of these factors (speed, current) on welding flaws by modifying one and altering the other, then conduct (hardness test, optical microscope, the fluid penetration test, and the visual test). With currents between (250-255-260) A and feed speeds between (112, 118, and 123) cm/min, inert gas welding is performed. Because to incompatibilities between feeding speed and current, the findings of the visual examination revealed flaws such as an incomplete welding region, spark, overlap, and a lack of uniformity. Findings that were within 250 A and 118 cm/min had the fewest faults. The liquid penetration was examined, and it revealed some fractures produced on by the temp differential. On the other hand, microscopic analysis revealed how current affected the heat in the welding region and, therefore, the microscopic structure of the specimens.

Volume 13, issue 3, 2022, pp.113-120. Download Full Text Article (PDF)