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Microstructure and Mechanical Properties of Electro-Slag Welds of Shipbuilding Steel Plate EH40

Electro-slag welding with heat input of 530kJ/cm was applied to 60mm thick shipbuilding plate EH40, and microstructure and mechanical properties of the weld joint were characterized. Different regions such as heat affected zone, fusion zone, weld metal and base metal are found across the weld joint by microstructure analysis. A narrow coarse grain heat affected zone consisting of acicular ferrite, polygonal ferrite and grain boundary ferrite is found, width of which is less than 1mm. Acicular ferrite (?? 10??m) and grain boundary ferrite is observed at weld metal, while fusion zone have a complex structure of acicular ferrite, grain boundary ferrite and ferrite side plate. Mechanical property tests show that the absorbed energy of WM, FL and CGHAZ at -20?? during Charpy impact test is more than 60J, no evident softening phenomenon occurred at heat affected zone, and other properties met the requirement.