ESTIMATION OF FRACTURE TOUGHNESS IN H.A.Z. OF SUBMERGED ARC WELD OF STRUCTURAL STEEL

Abstract

Weld joints in a welded structure are very important part in the view of failure and safety aspects. Heat Affected Zone (HAZ) play a significant role in determining the strength of weld. Before employing any welding procedure for a welded structure the mechanical properties and fracture toughness properties of this zone should be thoroughly studied. Because grain coarsening occurs in this zone and results in varying fracture mechanics properties. Due to this if a crack or defect already present in this region may propagate faster at lower energy values than other regions of a weldment. In this work fracture mechanics properties of Heat-Affect Zone of submerged arc welds of structural steel are studied. Tensile properties, Charpy V-notch impact properties, hardness properties and fracture toughness (J1c) for HAZ of these welds are estimated. Standard specimens were prepared as per ASTM standards. HAZ did not fail at lower energies in tensile loading but exhibited minimum resistance during charpy V-notch impact loading and showed significantly low fracture toughness value