Influence of twin welding process parameters on the quality of welded joints

Abstract

This paper describes the application of the robotic TWIN welding process as one of the high-performance arc welding processes. Unlike conventional methods, the TWIN system uses two separate wires that are electrically insulated and powered by separate power sources. This configuration allows for the formation of a single weld pool with precise control over the interaction between the electric arcs. The main contributions of implementing this system are reflected in: a significant increase in productivity, achieving higher welding speeds, achieving deeper penetration, and reducing thermal deformations. The practical part of the paper demonstrates the successful implementation of the system at the company Đuro Đaković Specijalna vozila. The basic parameters are described in detail, and a systematic analysis of their impact on joint integrity was conducted. The quality of the performed welds was evaluated through: geometric analysis (checking weld dimensions and shape), hardness testing (analysis of microstructure and mechanical properties in the heat-affected zone - HAZ), and non-destructive testing (NDT) application of ultrasonic testing for the detection of internal imperfections.