Most of the serious weldment failures lead to catastrophic consequences in terms of damage to other equipment, loss of production, and risks to workers’ health and safety. Hence there is motivation to find margin between safety and disaster. This necessitates guaranteeing the integrity of a welded structure even if a crack is present. Therefore influence of the material inhomogenity and residual stresses on deformation and fracture behavior needs to be described precisely. A comparison of the applied load with a convenient material parameter is necessary for this purpose. Fracture mechanics parameters J integral & CTOD have attracted great interest in recent years. In case of base materials, fracture mechanics works quite well, but some specific problems occur if fracture mechanics principles are applied when examining the toughness properties of welded joints. These problems are mainly caused by the large difference in material properties and residual stresses. Existing fracture toughness testing can predict fracture behavior, but does not sufficiently address the problem associated with weldment testing. Three SENB duplex stainless steel weldment specimens were tested as per ASTM E1820. This standard is not recommended for weldment, but since no standard is available for testing duplex stainless steel weldment, authors preferred to use it as reference. The aim of this work is to explore the possibility of using the test results in the reliable prediction of weldment fracture and its correlation with microstructure and hardness.
Fractography. .SIGMA. Phase Embrittlement of Duplex Stainless Steel Weldment.
