A study of electrogas welding process for vertical welding joint in the shipbuilding

In recent years, there are large amounts of order received for container carriers which are the biggest in the world ranging from 8,000 TEU to 10,000 TEU or above. The very large container carriers have minimum thickness of sheer strake, upper deck and hatch coaming about 65mm-90mm. Therefore, this study is performed in order for development of vertical welding process with high deposition rates to apply thick plate above 65mm thickness. Electrogas welding is productive method for vertical welding process with high deposition rate. Electrogas welding process with 1 pole and 2 poles has been developed to apply to vertical joint with thick plates in the shipbuilding yard. In this paper, various groove types were carried out to verify the feasibility of electrogas welding process for vertical welding joint. It was explained that the relationship of heat input to welding voltage and current. It was considered that the relationship of cross section to various groove types. It was found out that 20 degree is suitable groove angle for vertical welding process with high deposition rate. The experiments for electrogas welding processes with groove angle of 20 degree were executed to reduce excessive welding heat input and improve the material properties. The mechanical tests were carried out to verify the soundness of electrogas welding and met with good results which are satisfied with the ship's class regulations.