ABSTRACT

As it is known, ships are built by welded joining of sheets and various profiles. Welding, which was previously used as a repair method, has enabled the construction of large-scale ships using fully welded joints as a result of the developments in this field. Nowadays, shielded metal arc welding and gas metal arc welding are mostly used in shipbuilding. The materials used in ships depend on many variables such as the purpose of use of the ship, the place of use on the ship and the waters in which the navigation takes place. On the other hand, low-medium strength steels with carbon content in the range of 0.15-0.23% are generally used in ships due to their good toughness values, high corrosion resistance, low costs and high weldability. In light of this information, it will be extremely useful to comparatively examine the microstructural and mechanical properties of the welded zone as a result of welding low-medium strength shipbuilding steels with the mentioned methods. In this context, in this study, low-medium strength shipbuilding steel was joined with shielded metal arc welding and gas metal arc welding methods, and then the microstructure and mechanical properties of the weld zone were compared comparatively. As a result of the investigations, it was observed that a finer-grained microstructure was formed in the weld area as a result of gas metal arc welding. Also, result of the tests performed to determine the mechanical properties, better results were obtained in welded joints made with gas arc welding in all values of hardness, strength and impact toughness.