Narrow gap welding of titanium alloy samples with variable thickness and controlled magnetic field

Currently, narrow gap welding is considered the most effective method of arc welding of various metals of medium and large thickness. The main advantages of narrow gap welding are a significant reduction in the required amount of deposited metal (compared to cutting edges of a conventional shape) and, consequently, the consumption of filler wire, a reduction in the width of the weld and HAZ, as well as welding deformations. Reducing the amount of weld metal required to form a welded joint is especially important when welding titanium. To prevent lack of fusion, redistribution of arc heat is necessary. The use of the controlled magnetic field during narrow gap TIG welding allows to control the movement of the welding arc in narrow gap welding conditions. In this work, narrow gap welding will be carried out on the samples with variable thickness in the range of 45…60 mm. The work demonstrates, how the different thickness at the start and at the finish of welded detail impacts welding modes and heat source parameters. Results of investigations of the macrostructure of the welded joints are given.