Technology of thermal welding with ultrasonic weld joint treatment as applied to NPP formworks

The paper describes an innovative technology of thermal welding with ultrasonic weld joint treatment as applied to aluminum sliding formworks used in NPP construction. Ultrasonic treatment in the process of welding greatly increases the strength of formwork weld joints by reducing their residual stresses, grain size and degassing. The structure and properties of aluminum welds become identical to the base metal. Thermal welding with ultrasonic weld joint treatment will improve the reliability of welded joints and increase their time in service. The paper presents the results of theoretical and experimental studies of ultrasonic effects on the welded joints and heat-affected zone.