Filler materials for MAG welding with microjet cooling for truck frame repairs

The goal of this paper is to analyse the mechanical properties of the weld steel structure of car body truck frames following MAG welding repairs using various filler materials. The main role of welding conditions is connected with filler materials, welding technology, stress state and temperature. In the paper, the properties of steel structures after MAG welding with microjet cooling are presented. Weld metal deposits (WMDs) were prepared by using various welding wires with different chemical compositions. A WMD with various nickel content was examined using three different welding wires; simultaneously, a WMD with varied oxygen content was examined using different gas mixtures for microjet cooling. In this study, the metallographic structure and impact toughness of welded joints were analysed in terms of welding parameters. The amount of acicular ferrite (AF) in WMDs, with various amounts of nickel and oxygen after welding, was tested. The various steel deposits were checked with the variable content of manganese and silicon, as well as nickel. Gas mixtures of argon and carbon dioxide were used for microjet cooling.