Mohsen Mohammadijoo - MSc. at Materials Science and Engineering, Sharif University of Technology;
Mohammad Mosalanezhad - Head of Engineering Department, Petro Sina Arya Company;

Choice of material for seawater pipeline systems and offshore facilities will depend upon the particular environmental situation and the nature of the application. It will be affected by availability, price and political considerations, as well as the life expectancy; previous performance in similar situations will also influence the decision. Of the materials considered in this paper, the carbon steel is the one most widely used in oil and gas industries that we have studied on welding, corrosion and variations of its properties by changing the welding condition. In welding of pipelines and offshore facilities, atmospheric conditions can be effective on weld properties. Cracking and fracture are result of welding in this condition that could lead to expensive disbursement. In this research, effect of atmospheric condition discussed on microstructure, existence of porosities and offal as inter metallic compounds as well as mechanical properties of carbon steel equipment welding. Results of welding in different conditions show the porosities and offal that obtained from Non Destructive Tests (NDT). Also wind in limited velocity and rainfall with limited amount among welding lead to decrease in weld properties. Obviously, Existence of the porosities and the offal increase corrosion and reduce equipment life time

Materials Selection, Welding, Carbon Steel, Atmospheric Condition, NDT