Damages of burner pipes due to the working conditions and its repair welding

Repair welding represents the activity that restores the working capability of machine or construction caused by some damage due to working or environmental condition. Damages of burner pipes, part of the facility "Cold Rolling Mill" Steelwork in Smederevo, which appeared on welded joints during the manufacturing of the burner, and its repairing are presented in this paper. The damages occurred on welded joints along the weld as a result of the working conditions that burner was exposed to. Due to high temperatures that can reach up to 850 °C and "explosion" during gas burning, a crack may appear on the inner side of the burner. The base material of the burner pipes is stainless steel X12NiCrSi35-16. Repair welding is preceded by a series of operations, and one of them is the selection of an electrode. It turned out that inadequate selection of the electrode for repair welding had contributed to the occurrence of cracks on welded joints. Selecting a new electrode and examining its characteristics, as well as performing test welding of pipe that is still in exploitation, had confirmed the importance of proper selection of materials for repairing of burner pipes.