1995 Volume 35 Issue 10 Pages 1239-1247
High heat input electroslag welding (ESW) is widely used for the four side welding of 490 N/mm2 class steel between thick flange or web plate and diaphragm without Post Weld Heat Treatment (PWHT). The notch toughness of ESW weld metal is generally lower in the central part (C zone) then in the peripheral part (R zone) of the weld metal. This report has treated from metallurgical investigation the reason why the notch toughness of C zone is inferior to R zone. Moreover the improvement of the notch toughness in C zone has been investigated with the change of chemical element in the weld metal. As a result the reduction of Si content in weld metal is beneficial to improve the notch toughness of C zone and equalizes the ductility of both zones.