Influence of welding technology on residual stresses distribution

The Vitkovice j.s.c., a major producer of horizontal steam generator (SG), had to develop needed welding repair of primary collector sealing groove and carried out in real situation. Two kinds of technology were designed: MMAW and GTAW. The project of technology development was conducted in two phases. In the first phase the experimental program with measurement was prepared. Experiments were performed on the models in real scale. In the second phase numerical repair simulation both procedures, MMAW and GTAW, were used. The numerical simulation of repairs were solved as 3D multipass welding. Program SYSWELD by Framasoft+CSI was used for numerical repair simulation. Institute of Applied Mechanics Bmo Ltd. was assigned to estimate numerical simulation both weld procedures of welding repairs, to calculate residual stresses, compared influence of MMAW and GTAW and consequently solve the decreased component lifetime after repairs. The better technology was suggested to a customer.