FEATURES OF ONE-SIDED WELDING OF BIMETALLIC PIPES FOR OIL AND GAS INDUSTRY

During one sided welding of bimetallic pipes with combined welding materials (the root layer of the weld is made of high-alloyed corrosion-resistant materials, the filling and facing layers are made of low-alloyed materials) transition layer is formed. This layer has an extremely high hardness and tendency to crack formation, low ductility and impact toughness. To prevent the formation of a brittle transition layer, currently the entire weld is performed using expensive high-alloyed corrosion-resistant welding materials. That is why the search for technological solutions that allow obtaining a transition layer with satisfactory properties and performing one-sided welding of bimetal pipes using combined welding materials is a very urgent task. In this research a technological solution has been found for making a transition layer during one-sided welding of bimetallic pipes, which ensures the required level of hardness and mechanical characteristics of the welded joint. Welded joints of bimetallic pipes made using the experimental technology have a high level of strength and viscoplastic properties. The developed technology for welding bimetallic pipes allows reducing the cost of welding materials by 3–7 times, depending on the thickness of the welded pipes.